CentOS 7.0 - man page for fetchmail (centos section 1)

Linux & Unix Commands - Search Man Pages

Man Page or Keyword Search:   man
Select Man Page Set:       apropos Keyword Search (sections above)


fetchmail(1)			    fetchmail reference manual			     fetchmail(1)

NAME
       fetchmail - fetch mail from a POP, IMAP, ETRN, or ODMR-capable server

SYNOPSIS
       fetchmail [option...] [mailserver...]
       fetchmailconf

DESCRIPTION
       fetchmail  is  a  mail-retrieval  and  forwarding  utility;  it	fetches  mail from remote
       mailservers and forwards it to your local (client) machine's  delivery  system.	 You  can
       then  handle  the  retrieved mail using normal mail user agents such as mutt(1), elm(1) or
       Mail(1).  The fetchmail utility can be run in a daemon mode to repeatedly poll one or more
       systems at a specified interval.

       The  fetchmail  program	can  gather  mail from servers supporting any of the common mail-
       retrieval protocols: POP2 (legacy, to be removed from  future  release),  POP3,	IMAP2bis,
       IMAP4,  and  IMAP4rev1.	 It  can  also	use the ESMTP ETRN extension and ODMR.	(The RFCs
       describing all these protocols are listed at the end of this manual page.)

       While fetchmail is primarily intended to be used over on-demand TCP/IP links (such as SLIP
       or  PPP	connections),  it  may also be useful as a message transfer agent for sites which
       refuse for security reasons to permit (sender-initiated) SMTP transactions with sendmail.

   SUPPORT, TROUBLESHOOTING
       For troubleshooting, tracing and debugging, you need to increase fetchmail's verbosity  to
       actually  see  what  happens.  To  do that, please run both of the two following commands,
       adding all of the options you'd normally use.

	      env LC_ALL=C fetchmail -V -v --nodetach --nosyslog

	      (This command line prints in English how fetchmail understands your configuration.)

	      env LC_ALL=C fetchmail -vvv  --nodetach --nosyslog

	      (This command line actually runs fetchmail with verbose English output.)

       Also see item #G3 in fetchmail's FAQ <http://fetchmail.berlios.de/fetchmail-FAQ.html#G3>

       You can omit the LC_ALL=C part above if you want output in the  local  language	(if  sup-
       ported).  However if you are posting to mailing lists, please leave it in. The maintainers
       do not necessarily understand your language, please use English.

   CONCEPTS
       If fetchmail is used with a POP or an IMAP server (but not with ETRN or ODMR), it has  two
       fundamental modes of operation for each user account from which it retrieves mail: single-
       drop- and multidrop-mode.

       In singledrop-mode,
	      fetchmail assumes that all messages in the user's account  (mailbox)  are  intended
	      for  a  single recipient.  The identity of the recipient will either default to the
	      local user currently executing fetchmail, or will need to be  explicitly	specified
	      in the configuration file.

	      fetchmail  uses singledrop-mode when the fetchmailrc configuration contains at most
	      a single local user specification for a given server account.

       In multidrop-mode,
	      fetchmail assumes that the mail server account actually contains mail intended  for
	      any  number  of  different recipients.  Therefore, fetchmail must attempt to deduce
	      the proper "envelope recipient" from the mail headers of	each  message.	 In  this
	      mode of operation, fetchmail almost resembles a mail transfer agent (MTA).

	      Note that neither the POP nor IMAP protocols were intended for use in this fashion,
	      and hence envelope information is often  not  directly  available.   The	ISP  must
	      stores the envelope information in some message header and. The ISP must also store
	      one copy of the message per recipient. If either of  the	conditions  is	not  ful-
	      filled,  this process is unreliable, because fetchmail must then resort to guessing
	      the true envelope recipient(s) of a message. This usually fails  for  mailing  list
	      messages and Bcc:d mail, or mail for multiple recipients in your domain.

	      fetchmail  uses  multidrop-mode  when more than one local user and/or a wildcard is
	      specified for a particular server account in the configuration file.

       In ETRN and ODMR modes,
	      these considerations do not apply, as these protocols are based on SMTP, which pro-
	      vides  explicit envelope recipient information. These protocols always support mul-
	      tiple recipients.

       As each message is retrieved, fetchmail normally delivers it via SMTP to port  25  on  the
       machine it is running on (localhost), just as though it were being passed in over a normal
       TCP/IP link.  fetchmail provides the SMTP server with an envelope recipient derived in the
       manner  described  previously.	The  mail  will then be delivered according to your MTA's
       rules (the Mail Transfer Agent is usually sendmail(8), exim(8), or postfix(8)).	 Invoking
       your system's MDA (Mail Delivery Agent) is the duty of your MTA.  All the delivery-control
       mechanisms (such as .forward files) normally available through your system MTA  and  local
       delivery agents will therefore be applied as usual.

       If  your  fetchmail configuration sets a local MDA (see the --mda option), it will be used
       directly instead of talking SMTP to port 25.

       If the program fetchmailconf is available, it will assist you in setting up and editing	a
       fetchmailrc  configuration.   It runs under the X window system and requires that the lan-
       guage Python and the Tk toolkit (with Python bindings) be present on your system.  If  you
       are first setting up fetchmail for single-user mode, it is recommended that you use Novice
       mode.  Expert mode provides complete control of	fetchmail  configuration,  including  the
       multidrop features.  In either case, the 'Autoprobe' button will tell you the most capable
       protocol a given mailserver supports, and warn you of potential problems with that server.

GENERAL OPERATION
       The behavior of fetchmail is controlled by command-line options and a  run  control  file,
       ~/.fetchmailrc,	the syntax of which we describe in a later section (this file is what the
       fetchmailconf program edits).  Command-line options override ~/.fetchmailrc declarations.

       Each server name that you specify following the	options  on  the  command  line  will  be
       queried.   If you don't specify any servers on the command line, each 'poll' entry in your
       ~/.fetchmailrc file will be queried.

       To facilitate the use of fetchmail in scripts and pipelines,  it  returns  an  appropriate
       exit code upon termination -- see EXIT CODES below.

       The following options modify the behavior of fetchmail.	It is seldom necessary to specify
       any of these once you have a working .fetchmailrc file set up.

       Almost all options have a corresponding keyword which can be used to  declare  them  in	a
       .fetchmailrc file.

       Some  special  options  are  not  covered  here, but are documented instead in sections on
       AUTHENTICATION and DAEMON MODE which follow.

   General Options
       -V | --version
	      Displays the version information for your copy of fetchmail.  No mail fetch is per-
	      formed.	Instead, for each server specified, all the option information that would
	      be computed if fetchmail were connecting to that server  is  displayed.	Any  non-
	      printables  in  passwords  or  other  string  names are shown as backslashed C-like
	      escape sequences.  This option is useful for verifying that your	options  are  set
	      the way you want them.

       -c | --check
	      Return  a  status  code to indicate whether there is mail waiting, without actually
	      fetching or deleting mail (see EXIT CODES below).  This  option  turns  off  daemon
	      mode (in which it would be useless).  It doesn't play well with queries to multiple
	      sites, and doesn't work with ETRN or ODMR.  It will return a false positive if  you
	      leave  read but undeleted mail in your server mailbox and your fetch protocol can't
	      tell kept messages from new ones.  This means it will work with IMAP, not work with
	      POP2, and may occasionally flake out under POP3.

       -s | --silent
	      Silent  mode.   Suppresses all progress/status messages that are normally echoed to
	      standard output during a fetch (but does not suppress actual error messages).   The
	      --verbose option overrides this.

       -v | --verbose
	      Verbose mode.  All control messages passed between fetchmail and the mailserver are
	      echoed to stdout.  Overrides --silent.  Doubling this option (-v -v)  causes  extra
	      diagnostic information to be printed.

       --nosoftbounce
	      (since v6.3.10, Keyword: set no softbounce, since v6.3.10)
	      Hard  bounce  mode. All permanent delivery errors cause messages to be deleted from
	      the upstream server, see "no softbounce" below.

       --softbounce
	      (since v6.3.10, Keyword: set softbounce, since v6.3.10)
	      Soft bounce mode. All permanent delivery errors cause messages to be  left  on  the
	      upstream	server if the protocol supports that. Default to match historic fetchmail
	      documentation, to be changed to hard bounce mode in the next fetchmail release.

   Disposal Options
       -a | --all | (since v6.3.3) --fetchall
	      (Keyword: fetchall, since v3.0)
	      Retrieve both old (seen) and new messages from the mailserver.  The default  is  to
	      fetch  only  messages the server has not marked seen.  Under POP3, this option also
	      forces the use of RETR rather than TOP.  Note that POP2 retrieval behaves as though
	      --all  is  always  on  (see RETRIEVAL FAILURE MODES below) and this option does not
	      work with ETRN or ODMR.  While the -a and --all command-line  and  fetchall  rcfile
	      options have been supported for a long time, the --fetchall command-line option was
	      added in v6.3.3.

       -k | --keep
	      (Keyword: keep)
	      Keep retrieved messages on the remote mailserver.  Normally, messages  are  deleted
	      from  the  folder on the mailserver after they have been retrieved.  Specifying the
	      keep option causes retrieved messages to remain in your folder on  the  mailserver.
	      This  option  does not work with ETRN or ODMR. If used with POP3, it is recommended
	      to also specify the --uidl option or uidl keyword.

       -K | --nokeep
	      (Keyword: nokeep)
	      Delete retrieved messages from the remote mailserver.  This option forces retrieved
	      mail  to	be  deleted.  It may be useful if you have specified a default of keep in
	      your .fetchmailrc.  This option is forced on with ETRN and ODMR.

       -F | --flush
	      (Keyword: flush)
	      POP3/IMAP only.  This is a dangerous option and  can  cause  mail  loss  when  used
	      improperly.  It  deletes	old (seen) messages from the mailserver before retrieving
	      new messages.  Warning: This can cause mail loss if you check your mail with  other
	      clients  than  fetchmail,  and  cause  fetchmail	to  delete a message it had never
	      fetched before.  It can also cause mail loss if the mail server marks  the  message
	      seen  after  retrieval  (IMAP2 servers). You should probably not use this option in
	      your configuration file. If you use it with POP3, you must use the  'uidl'  option.
	      What  you  probably  want  is  the default setting: if you don't specify '-k', then
	      fetchmail will automatically delete messages after successful delivery.

       --limitflush
	      POP3/IMAP only, since version 6.3.0.  Delete oversized messages from the mailserver
	      before  retrieving new messages. The size limit should be separately specified with
	      the --limit option.  This option does not work with ETRN or ODMR.

   Protocol and Query Options
       -p <proto> | --proto <proto> | --protocol <proto>
	      (Keyword: proto[col])
	      Specify the protocol to use when communicating with the remote mailserver.   If  no
	      protocol is specified, the default is AUTO.  proto may be one of the following:

	      AUTO   Tries  IMAP, POP3, and POP2 (skipping any of these for which support has not
		     been compiled in).

	      POP2   Post Office Protocol 2 (legacy, to be removed from future release)

	      POP3   Post Office Protocol 3

	      APOP   Use POP3 with old-fashioned MD5-challenge	authentication.   Considered  not
		     resistant to man-in-the-middle attacks.

	      RPOP   Use POP3 with RPOP authentication.

	      KPOP   Use POP3 with Kerberos V4 authentication on port 1109.

	      SDPS   Use POP3 with Demon Internet's SDPS extensions.

	      IMAP   IMAP2bis,	IMAP4,	or IMAP4rev1 (fetchmail automatically detects their capa-
		     bilities).

	      ETRN   Use the ESMTP ETRN option.

	      ODMR   Use the the On-Demand Mail Relay ESMTP profile.

       All these alternatives work in basically the same way (communicating with standard  server
       daemons	to fetch mail already delivered to a mailbox on the server) except ETRN and ODMR.
       The ETRN mode allows you to ask a compliant ESMTP server (such as BSD sendmail at  release
       8.8.0  or  higher) to immediately open a sender-SMTP connection to your client machine and
       begin forwarding any items addressed to your client machine in the server's queue of unde-
       livered mail.   The ODMR mode requires an ODMR-capable server and works similarly to ETRN,
       except that it does not require the client machine to have a static DNS.

       -U | --uidl
	      (Keyword: uidl)
	      Force UIDL use (effective only with POP3).  Force client-side tracking of 'newness'
	      of messages (UIDL stands for "unique ID listing" and is described in RFC1939).  Use
	      with 'keep' to use a mailbox as a baby news drop for a group  of	users.	The  fact
	      that seen messages are skipped is logged, unless error logging is done through sys-
	      log while running in daemon mode.  Note that  fetchmail  may  automatically  enable
	      this  option depending on upstream server capabilities.  Note also that this option
	      may be removed and  forced  enabled  in  a  future  fetchmail  version.  See  also:
	      --idfile.

       --idle (since 6.3.3)
	      (Keyword: idle, since before 6.0.0)
	      Enable  IDLE  use  (effective  only  with IMAP). Note that this works with only one
	      folder at a given time.  While the idle rcfile keyword had  been	supported  for	a
	      long  time,  the	--idle	command-line  option was added in version 6.3.3. IDLE use
	      means that fetchmail tells the IMAP server to send notice of new messages, so  they
	      can be retrieved sooner than would be possible with regular polls.

       -P <portnumber> | --service <servicename>
	      (Keyword: service) Since version 6.3.0.
	      The  service  option  permits you to specify a service name to connect to.  You can
	      specify a decimal port number here, if your services database  lacks  the  required
	      service-port  assignments.  See  the  FAQ  item R12 and the --ssl documentation for
	      details. This replaces the older --port option.

       --port <portnumber>
	      (Keyword: port)
	      Obsolete version of --service that does not take service names.  Note: this  option
	      may be removed from a future version.

       --principal <principal>
	      (Keyword: principal)
	      The  principal option permits you to specify a service principal for mutual authen-
	      tication.  This is applicable to POP3 or IMAP with Kerberos 4 authentication  only.
	      It  does not apply to Kerberos 5 or GSSAPI.  This option may be removed in a future
	      fetchmail version.

       -t <seconds> | --timeout <seconds>
	      (Keyword: timeout)
	      The timeout option allows you to set a server-nonresponse timeout in seconds.  If a
	      mailserver  does	not  send a greeting message or respond to commands for the given
	      number of seconds, fetchmail will drop the connection to it.  Without such a  time-
	      out  fetchmail  might hang until the TCP connection times out, trying to fetch mail
	      from a down host, which may be very long.  This would be particularly annoying  for
	      a  fetchmail  running  in  the background.  There is a default timeout which fetch-
	      mail -V will report.  If a given connection receives too many timeouts  in  succes-
	      sion,  fetchmail	will consider it wedged and stop retrying.  The calling user will
	      be notified by email if this happens.

	      Beginning with fetchmail 6.3.10, the SMTP client uses the recommended minimum time-
	      outs  from  RFC-5321  while waiting for the SMTP/LMTP server it is talking to.  You
	      can raise the timeouts even more, but you cannot shorten them. This is to  avoid	a
	      painful  situation  where  fetchmail  has  been  configured with a short timeout (a
	      minute or less), ships a long message (many MBytes) to the local	MTA,  which  then
	      takes  longer  than  timeout  to respond "OK", which it eventually will; that would
	      mean the mail gets delivered properly, but fetchmail cannot notice it and will thus
	      refetch this big message over and over again.

       --plugin <command>
	      (Keyword: plugin)
	      The  plugin  option allows you to use an external program to establish the TCP con-
	      nection.	This is useful if you want to use ssh, or need some  special  firewalling
	      setup.   The  program  will  be looked up in $PATH and can optionally be passed the
	      hostname and port as arguments using "%h" and  "%p"  respectively  (note	that  the
	      interpolation logic is rather primitive, and these tokens must be bounded by white-
	      space or beginning of string or end of string).  Fetchmail will write to the  plug-
	      in's stdin and read from the plugin's stdout.

       --plugout <command>
	      (Keyword: plugout)
	      Identical  to  the  plugin  option above, but this one is used for the SMTP connec-
	      tions.

       -r <name> | --folder <name>
	      (Keyword: folder[s])
	      Causes a specified non-default mail folder on the  mailserver  (or  comma-separated
	      list  of	folders) to be retrieved.  The syntax of the folder name is server-depen-
	      dent.  This option is not available under POP3, ETRN, or ODMR.

       --tracepolls
	      (Keyword: tracepolls)
	      Tell fetchmail to poll trace information in  the	form  'polling	account  %s'  and
	      'folder  %s'  to the Received line it generates, where the %s parts are replaced by
	      the user's remote name, the poll label, and the folder  (mailbox)  where	available
	      (the  Received  header also normally includes the server's true name).  This can be
	      used to facilitate mail filtering based on the account it is being  received  from.
	      The folder information is written only since version 6.3.4.

       --ssl  (Keyword: ssl)
	      Causes  the  connection to the mail server to be encrypted via SSL.  Connect to the
	      server using the specified base protocol over a connection  secured  by  SSL.  This
	      option  defeats opportunistic starttls negotiation. It is highly recommended to use
	      --sslproto 'SSL3' --sslcertck to validate the certificates presented by the  server
	      and  defeat  the	obsolete  SSLv2 negotiation. More information is available in the
	      README.SSL file that ships with fetchmail.

	      Note that fetchmail may still try to negotiate SSL through starttls  even  if  this
	      option  is  omitted.  You  can use the --sslproto option to defeat this behavior or
	      tell fetchmail to negotiate a particular SSL protocol.

	      If no port is specified, the connection is attempted to the well known port of  the
	      SSL version of the base protocol.  This is generally a different port than the port
	      used by the base protocol.  For IMAP, this is port 143 for the clear  protocol  and
	      port  993 for the SSL secured protocol, for POP3, it is port 110 for the clear text
	      and port 995 for the encrypted variant.

	      If your system lacks the corresponding entries from /etc/services, see  the  --ser-
	      vice  option and specify the numeric port number as given in the previous paragraph
	      (unless your ISP had directed you to different ports, which is uncommon however).

       --sslcert <name>
	      (Keyword: sslcert)
	      For certificate-based client authentication.  Some SSL  encrypted  servers  require
	      client  side  keys  and  certificates  for  authentication.  In most cases, this is
	      optional.  This specifies the location of the public key	certificate  to  be  pre-
	      sented  to  the  server  at  the	time  the  SSL session is established.	It is not
	      required (but may be provided) if the server does not require it.  It  may  be  the
	      same  file  as  the private key (combined key and certificate file) but this is not
	      recommended. Also see --sslkey below.

	      NOTE: If you use client authentication, the user name is fetched from the  certifi-
	      cate's CommonName and overrides the name set with --user.

       --sslkey <name>
	      (Keyword: sslkey)
	      Specifies  the  file  name  of the client side private SSL key.  Some SSL encrypted
	      servers require client side keys and  certificates  for  authentication.	 In  most
	      cases,  this  is	optional.  This specifies the location of the private key used to
	      sign transactions with the server at the time the SSL session is	established.   It
	      is  not required (but may be provided) if the server does not require it. It may be
	      the same file as the public key (combined key and certificate file) but this is not
	      recommended.

	      If  a  password  is required to unlock the key, it will be prompted for at the time
	      just prior to establishing the session to the server.  This can cause some  compli-
	      cations in daemon mode.

	      Also see --sslcert above.

       --sslproto <name>
	      (Keyword: sslproto)
	      Forces  an  SSL/TLS  protocol. Possible values are '', 'SSL2' (not supported on all
	      systems), 'SSL23', (use of these two values is discouraged and should only be  used
	      as  a  last  resort)  'SSL3',  and 'TLS1'.  The default behaviour if this option is
	      unset is: for connections without --ssl, use 'TLS1' so that fetchmail  will  oppor-
	      tunistically  try  STARTTLS  negotiation	with  TLS1. You can configure this option
	      explicitly if the default handshake (TLS1 if --ssl is not used) does not	work  for
	      your server.

	      Use  this  option with 'TLS1' value to enforce a STARTTLS connection. In this mode,
	      it is highly recommended to also use --sslcertck (see below).  Note that this  will
	      then cause fetchmail v6.3.19 to force STARTTLS negotiation even if it is not adver-
	      tised by the server.

	      To defeat opportunistic TLSv1 negotiation when the server  advertises  STARTTLS  or
	      STLS,  and use a cleartext connection use ''.  This option, even if the argument is
	      the empty string, will also suppress the diagnostic 'SERVER: opportunistic  upgrade
	      to  TLS.'  message  in  verbose  mode.  The default is to try appropriate protocols
	      depending on context.

       --sslcertck
	      (Keyword: sslcertck)
	      Causes fetchmail to strictly check the server certificate against a  set	of  local
	      trusted  certificates  (see the sslcertfile and sslcertpath options). If the server
	      certificate cannot be obtained or  is  not  signed  by  one  of  the  trusted  ones
	      (directly  or  indirectly), the SSL connection will fail, regardless of the sslfin-
	      gerprint option.

	      Note that CRL (certificate revocation lists) are only supported  in  OpenSSL  0.9.7
	      and  newer!  Your  system  clock should also be reasonably accurate when using this
	      option.

	      Note that this optional behavior may become default behavior  in	future	fetchmail
	      versions.

       --sslcertfile <file>
	      (Keyword: sslcertfile, since v6.3.17)
	      Sets  the file fetchmail uses to look up local certificates.  The default is empty.
	      This can be given in addition to --sslcertpath below, and certificates specified in
	      --sslcertfile  will  be processed before those in --sslcertpath.	The option can be
	      used in addition to --sslcertpath.

	      The file is a text file. It contains the concatenation of trusted  CA  certificates
	      in PEM format.

	      Note  that  using this option will suppress loading the default SSL trusted CA cer-
	      tificates   file	 unless    you	  set	 the	environment    variable    FETCH-
	      MAIL_INCLUDE_DEFAULT_X509_CA_CERTS to a non-empty value.

       --sslcertpath <directory>
	      (Keyword: sslcertpath)
	      Sets  the  directory  fetchmail  uses to look up local certificates. The default is
	      your OpenSSL default directory. The  directory  must  be	hashed	the  way  OpenSSL
	      expects  it - every time you add or modify a certificate in the directory, you need
	      to use the c_rehash tool (which comes with OpenSSL  in  the  tools/  subdirectory).
	      Also,  after  OpenSSL  upgrades,	you  may  need to run c_rehash; particularly when
	      upgrading from 0.9.X to 1.0.0.

	      This can be given in addition to --sslcertfile  above,  which  see  for  precedence
	      rules.

	      Note  that  using  this option will suppress adding the default SSL trusted CA cer-
	      tificates   directory   unless   you   set   the	 environment   variable    FETCH-
	      MAIL_INCLUDE_DEFAULT_X509_CA_CERTS to a non-empty value.

       --sslcommonname <common name>
	      (Keyword: sslcommonname; since v6.3.9)
	      Use  of  this  option is discouraged. Before using it, contact the administrator of
	      your upstream server and ask for a proper SSL certificate to be used. If that  can-
	      not  be  attained,  this	option	can be used to specify the name (CommonName) that
	      fetchmail expects on the server certificate.  A correctly  configured  server  will
	      have this set to the hostname by which it is reached, and by default fetchmail will
	      expect as much. Use this option when the CommonName is set to some other value,  to
	      avoid  the  "Server  CommonName  mismatch" warning, and only if the upstream server
	      can't be made to use proper certificates.

       --sslfingerprint <fingerprint>
	      (Keyword: sslfingerprint)
	      Specify the fingerprint of the server key (an MD5 hash of the key)  in  hexadecimal
	      notation with colons separating groups of two digits. The letter hex digits must be
	      in upper case. This is the default format OpenSSL uses, and the one fetchmail  uses
	      to report the fingerprint when an SSL connection is established. When this is spec-
	      ified, fetchmail will compare the server key fingerprint with the  given	one,  and
	      the  connection will fail if they do not match regardless of the sslcertck setting.
	      The connection will also fail if fetchmail cannot obtain an  SSL	certificate  from
	      the  server.  This can be used to prevent man-in-the-middle attacks, but the finger
	      print from the server needs to be obtained or verified over a secure  channel,  and
	      certainly not over the same Internet connection that fetchmail would use.

	      Using  this option will prevent printing certificate verification errors as long as
	      --sslcertck is unset.

	      To obtain the fingerprint of a certificate stored in the file cert.pem, try:

		   openssl x509 -in cert.pem -noout -md5 -fingerprint

	      For details, see x509(1ssl).

   Delivery Control Options
       -S <hosts> | --smtphost <hosts>
	      (Keyword: smtp[host])
	      Specify a hunt list of hosts to forward mail to (one or more hostnames, comma-sepa-
	      rated).  Hosts  are  tried in list order; the first one that is up becomes the for-
	      warding target for the current run.  If this option is not  specified,  'localhost'
	      is  used	as  the default.  Each hostname may have a port number following the host
	      name.  The port number is separated from the host name by a slash; the default port
	      is  "smtp".   If you specify an absolute path name (beginning with a /), it will be
	      interpreted as the name of a UNIX socket accepting LMTP  connections  (such  as  is
	      supported by the Cyrus IMAP daemon) Example:

		   --smtphost server1,server2/2525,server3,/var/imap/socket/lmtp

	      This option can be used with ODMR, and will make fetchmail a relay between the ODMR
	      server and SMTP or LMTP receiver.

       --fetchdomains <hosts>
	      (Keyword: fetchdomains)
	      In ETRN or ODMR mode, this option specifies the list of domains the  server  should
	      ship mail for once the connection is turned around.  The default is the FQDN of the
	      machine running fetchmail.

       -D <domain> | --smtpaddress <domain>
	      (Keyword: smtpaddress)
	      Specify the domain to be appended to addresses in RCPT TO lines  shipped	to  SMTP.
	      When  this  is  not  specified, the name of the SMTP server (as specified by --smt-
	      phost) is used for SMTP/LMTP and 'localhost' is used for UNIX socket/BSMTP.

       --smtpname <user@domain>
	      (Keyword: smtpname)
	      Specify the domain and user to be put in	RCPT  TO  lines  shipped  to  SMTP.   The
	      default user is the current local user.

       -Z <nnn> | --antispam <nnn[, nnn]...>
	      (Keyword: antispam)
	      Specifies  the  list  of	numeric SMTP errors that are to be interpreted as a spam-
	      block response from the listener.  A value of -1 disables  this  option.	 For  the
	      command-line option, the list values should be comma-separated.

       -m <command> | --mda <command>
	      (Keyword: mda)
	      This  option  lets  fetchmail  use  a  Message or Local Delivery Agent (MDA or LDA)
	      directly, rather than forward via SMTP or LMTP.

	      To avoid losing mail, use this option only with MDAs like  maildrop  or  MTAs  like
	      sendmail	that  exit  with a nonzero status on disk-full and other delivery errors;
	      the nonzero status tells fetchmail that delivery failed and  prevents  the  message
	      from being deleted on the server.

	      If  fetchmail is running as root, it sets its user id while delivering mail through
	      an MDA as follows:  First, the FETCHMAILUSER, LOGNAME, and USER  environment  vari-
	      ables are checked in this order. The value of the first variable from his list that
	      is defined (even if it is empty!) is looked up in the system user database. If none
	      of  the  variables  is  defined, fetchmail will use the real user id it was started
	      with. If one of the variables was defined, but the user stated there  isn't  found,
	      fetchmail  continues  running  as root, without checking remaining variables on the
	      list.  Practically, this means that if you run fetchmail as root (not recommended),
	      it  is most useful to define the FETCHMAILUSER environment variable to set the user
	      that the MDA should run as. Some MDAs (such as maildrop) are designed to be  setuid
	      root  and  setuid  to the recipient's user id, so you don't lose functionality this
	      way even when running fetchmail as unprivileged user.  Check the MDA's  manual  for
	      details.

	      Some  possible  MDAs  are  "/usr/sbin/sendmail  -i -f %F -- %T" (Note: some several
	      older or vendor sendmail versions mistake -- for an address, rather than an indica-
	      tor   to	 mark	the   end   of	the  option  arguments),  "/usr/bin/deliver"  and
	      "/usr/bin/maildrop -d %T".  Local delivery addresses will be inserted into the  MDA
	      command  wherever  you place a %T; the mail message's From address will be inserted
	      where you place an %F.

	      Do NOT enclose the %F or %T string in single quotes!  For both %T and %F, fetchmail
	      encloses	the addresses in single quotes ('), after removing any single quotes they
	      may contain, before the MDA command is passed to the shell.

	      Do NOT use an MDA invocation that dispatches on the  contents  of  To/Cc/Bcc,  like
	      "sendmail  -i  -t"  or "qmail-inject", it will create mail loops and bring the just
	      wrath of many postmasters down upon your head.  This is one of  the  most  frequent
	      configuration errors!

	      Also,  do  not  try to combine multidrop mode with an MDA such as maildrop that can
	      only accept one address, unless your upstream stores one copy of	the  message  per
	      recipient and transports the envelope recipient in a header; you will lose mail.

	      The  well-known  procmail(1)  package  is very hard to configure properly, it has a
	      very nasty "fall through to the next rule" behavior on delivery errors (even tempo-
	      rary ones, such as out of disk space if another user's mail daemon copies the mail-
	      box around to purge old messages), so your mail will end up in  the  wrong  mailbox
	      sooner  or  later.  The  proper procmail configuration is outside the scope of this
	      document. Using maildrop(1) is usually much easier, and many users find the  filter
	      syntax used by maildrop easier to understand.

	      Finally,	we  strongly  advise  that you do not use qmail-inject.  The command line
	      interface is non-standard without providing benefits for typical use, and fetchmail
	      makes  no attempts to accommodate qmail-inject's deviations from the standard. Some
	      of qmail-inject's command-line and environment options are actually  dangerous  and
	      can cause broken threads, non-detected duplicate messages and forwarding loops.

       --lmtp (Keyword: lmtp)
	      Cause  delivery  via  LMTP (Local Mail Transfer Protocol).  A service host and port
	      must be explicitly specified on each host in the smtphost hunt list (see above)  if
	      this option is selected; the default port 25 will (in accordance with RFC 2033) not
	      be accepted.

       --bsmtp <filename>
	      (Keyword: bsmtp)
	      Append fetched mail to a BSMTP file.  This simply contains the SMTP  commands  that
	      would normally be generated by fetchmail when passing mail to an SMTP listener dae-
	      mon.

	      An argument of '-' causes the SMTP batch to be written to standard output, which is
	      of  limited  use:  this only makes sense for debugging, because fetchmail's regular
	      output is interspersed on the same channel, so this isn't suitable for mail  deliv-
	      ery. This special mode may be removed in a later release.

	      Note  that fetchmail's reconstruction of MAIL FROM and RCPT TO lines is not guaran-
	      teed correct; the caveats discussed under THE USE AND ABUSE OF MULTIDROP	MAILBOXES
	      below apply.  This mode has precedence before --mda and SMTP/LMTP.

       --bad-header {reject|accept}
	      (Keyword: bad-header; since v6.3.15)
	      Specify how fetchmail is supposed to treat messages with bad headers, i. e. headers
	      with bad syntax. Traditionally, fetchmail has rejected such messages, but some dis-
	      tributors  modified fetchmail to accept them. You can now configure fetchmail's be-
	      haviour per server.

   Resource Limit Control Options
       -l <maxbytes> | --limit <maxbytes>
	      (Keyword: limit)
	      Takes a maximum octet size argument, where 0 is the default and  also  the  special
	      value  designating "no limit".  If nonzero, messages larger than this size will not
	      be fetched and will be left on the server (in  foreground  sessions,  the  progress
	      messages	will  note that they are "oversized").	If the fetch protocol permits (in
	      particular, under IMAP or POP3 without the fetchall option) the message will not be
	      marked seen.

	      An  explicit  --limit  of 0 overrides any limits set in your run control file. This
	      option is intended for those needing to strictly control fetch time due  to  expen-
	      sive and variable phone rates.

	      Combined	with --limitflush, it can be used to delete oversized messages waiting on
	      a server.  In daemon mode, oversize notifications are mailed to  the  calling  user
	      (see the --warnings option). This option does not work with ETRN or ODMR.

       -w <interval> | --warnings <interval>
	      (Keyword: warnings)
	      Takes  an  interval  in  seconds.  When you call fetchmail with a 'limit' option in
	      daemon mode, this controls the interval at which warnings about oversized  messages
	      are  mailed to the calling user (or the user specified by the 'postmaster' option).
	      One such notification is always mailed at the end of the the first  poll	that  the
	      oversized  message  is  detected.   Thereafter, re-notification is suppressed until
	      after the warning interval elapses (it will take place at the end of the first fol-
	      lowing poll).

       -b <count> | --batchlimit <count>
	      (Keyword: batchlimit)
	      Specify  the  maximum  number  of messages that will be shipped to an SMTP listener
	      before the connection is deliberately torn down and rebuilt (defaults to 0, meaning
	      no limit).  An explicit --batchlimit of 0 overrides any limits set in your run con-
	      trol file.  While sendmail(8) normally initiates delivery of a message  immediately
	      after  receiving	the  message  terminator,  some SMTP listeners are not so prompt.
	      MTAs like smail(8) may wait till the delivery socket is shut down to deliver.  This
	      may  produce annoying delays when fetchmail is processing very large batches.  Set-
	      ting the batch limit to some nonzero size will prevent these delays.   This  option
	      does not work with ETRN or ODMR.

       -B <number> | --fetchlimit <number>
	      (Keyword: fetchlimit)
	      Limit  the  number  of  messages accepted from a given server in a single poll.  By
	      default there is no limit. An explicit --fetchlimit of 0 overrides any  limits  set
	      in your run control file.  This option does not work with ETRN or ODMR.

       --fetchsizelimit <number>
	      (Keyword: fetchsizelimit)
	      Limit  the  number  of  sizes  of messages accepted from a given server in a single
	      transaction.  This option is useful in reducing the delay in downloading the  first
	      mail  when  there are too many mails in the mailbox.  By default, the limit is 100.
	      If set to 0, sizes of all messages are downloaded at the start.  This  option  does
	      not work with ETRN or ODMR.  For POP3, the only valid non-zero value is 1.

       --fastuidl <number>
	      (Keyword: fastuidl)
	      Do a binary instead of linear search for the first unseen UID. Binary search avoids
	      downloading the UIDs of all mails. This saves  time  (especially	in  daemon  mode)
	      where  downloading  the  same set of UIDs in each poll is a waste of bandwidth. The
	      number 'n' indicates how rarely a linear search should be  done.	In  daemon  mode,
	      linear  search  is  used	once followed by binary searches in 'n-1' polls if 'n' is
	      greater than 1; binary search is always used if 'n' is 1; linear search  is  always
	      used  if 'n' is 0. In non-daemon mode, binary search is used if 'n' is 1; otherwise
	      linear search is used. The default value of 'n' is 4.  This option works with  POP3
	      only.

       -e <count> | --expunge <count>
	      (Keyword: expunge)
	      Arrange  for  deletions  to  be made final after a given number of messages.  Under
	      POP2 or POP3, fetchmail cannot make deletions final without sending QUIT and ending
	      the session -- with this option on, fetchmail will break a long mail retrieval ses-
	      sion into multiple sub-sessions, sending QUIT after each	sub-session.  This  is	a
	      good  defense  against  line drops on POP3 servers.  Under IMAP, fetchmail normally
	      issues an EXPUNGE command after each deletion in order to force the deletion to  be
	      done  immediately.   This is safest when your connection to the server is flaky and
	      expensive, as it avoids resending duplicate mail after a	line  hit.   However,  on
	      large mailboxes the overhead of re-indexing after every message can slam the server
	      pretty hard, so if your connection is reliable it is good to do expunges less  fre-
	      quently.	 Also  note that some servers enforce a delay of a few seconds after each
	      quit, so fetchmail may not be able to get back in immediately after an  expunge  --
	      you  may	see  "lock busy" errors if this happens. If you specify this option to an
	      integer N, it tells fetchmail to only issue expunges on every Nth delete.  An argu-
	      ment of zero suppresses expunges entirely (so no expunges at all will be done until
	      the end of run).	This option does not work with ETRN or ODMR.

   Authentication Options
       -u <name> | --user <name> | --username <name>
	      (Keyword: user[name])
	      Specifies the user identification to be used when logging  in  to  the  mailserver.
	      The appropriate user identification is both server and user-dependent.  The default
	      is your login name on the client machine	that  is  running  fetchmail.	See  USER
	      AUTHENTICATION below for a complete description.

       -I <specification> | --interface <specification>
	      (Keyword: interface)
	      Require  that a specific interface device be up and have a specific local or remote
	      IPv4 (IPv6 is not supported by this option yet) address (or range) before  polling.
	      Frequently  fetchmail  is  used  over a transient point-to-point TCP/IP link estab-
	      lished directly to a mailserver via SLIP or PPP.	That is a relatively secure chan-
	      nel.   But  when other TCP/IP routes to the mailserver exist (e.g. when the link is
	      connected to an alternate ISP), your username and password  may  be  vulnerable  to
	      snooping	(especially  when  daemon  mode  automatically polls for mail, shipping a
	      clear password over the net at predictable intervals).  The --interface option  may
	      be  used to prevent this.  When the specified link is not up or is not connected to
	      a matching IP address, polling will be skipped.  The format is:

		   interface/iii.iii.iii.iii[/mmm.mmm.mmm.mmm]

	      The field before the first slash is the interface name (i.e. sl0, ppp0 etc.).   The
	      field  before  the  second slash is the acceptable IP address.  The field after the
	      second slash is a mask which specifies a range of IP addresses to  accept.   If  no
	      mask  is	present 255.255.255.255 is assumed (i.e. an exact match).  This option is
	      currently only supported under Linux and FreeBSD. Please see  the  monitor  section
	      for below for FreeBSD specific information.

	      Note that this option may be removed from a future fetchmail version.

       -M <interface> | --monitor <interface>
	      (Keyword: monitor)
	      Daemon  mode  can  cause transient links which are automatically taken down after a
	      period of inactivity (e.g. PPP links) to remain up indefinitely.	This option iden-
	      tifies  a  system  TCP/IP  interface to be monitored for activity.  After each poll
	      interval, if the link is up but no other activity has occurred on  the  link,  then
	      the  poll  will  be  skipped.  However, when fetchmail is woken up by a signal, the
	      monitor check is skipped and the poll goes through unconditionally.  This option is
	      currently  only  supported  under Linux and FreeBSD.  For the monitor and interface
	      options to work for non root users under FreeBSD,  the  fetchmail  binary  must  be
	      installed  SGID  kmem.   This would be a security hole, but fetchmail runs with the
	      effective GID set to that of the kmem group only when interface data is being  col-
	      lected.

	      Note that this option may be removed from a future fetchmail version.

       --auth <type>
	      (Keyword: auth[enticate])
	      This  option permits you to specify an authentication type (see USER AUTHENTICATION
	      below for details).  The possible values are any, password,  kerberos_v5,  kerberos
	      (or,  for  excruciating  exactness,  kerberos_v4), gssapi, cram-md5, otp, ntlm, msn
	      (only for POP3), external (only IMAP) and ssh.  When any (the  default)  is  speci-
	      fied,  fetchmail	tries first methods that don't require a password (EXTERNAL, GSS-
	      API, KERBEROS IV, KERBEROS 5); then it looks for methods that  mask  your  password
	      (CRAM-MD5,  NTLM,  X-OTP	- note that MSN is only supported for POP3, but not auto-
	      probed); and only if the server doesn't support any of  those  will  it  ship  your
	      password	en clair.  Other values may be used to force various authentication meth-
	      ods (ssh suppresses authentication and is thus useful for IMAP PREAUTH).	(external
	      suppresses  authentication  and is thus useful for IMAP EXTERNAL).  Any value other
	      than password, cram-md5, ntlm, msn or otp suppresses fetchmail's normal inquiry for
	      a password.  Specify ssh when you are using an end-to-end secure connection such as
	      an ssh tunnel; specify external when you use TLS	with  client  authentication  and
	      specify gssapi or kerberos_v4 if you are using a protocol variant that employs GSS-
	      API or K4.  Choosing KPOP protocol automatically selects	Kerberos  authentication.
	      This  option  does  not  work  with  ETRN.   GSSAPI  service names are in line with
	      RFC-2743 and IANA registrations, see Generic Security Service Application Program
	      Interface (GSSAPI)/Kerberos/Simple Authentication and Security Layer (SASL) Service
	      Names <http://www.iana.org/assignments/gssapi-service-names/>.

   Miscellaneous Options
       -f <pathname> | --fetchmailrc <pathname>
	      Specify a non-default name for the ~/.fetchmailrc run control file.   The  pathname
	      argument	must be either "-" (a single dash, meaning to read the configuration from
	      standard input) or a filename.  Unless the --version option is  also  on,  a  named
	      file argument must have permissions no more open than 0700 (u=rwx,g=,o=) or else be
	      /dev/null.

       -i <pathname> | --idfile <pathname>
	      (Keyword: idfile)
	      Specify an alternate name for the .fetchids file used to save message  UIDs.  NOTE:
	      since  fetchmail	6.3.0,	write  access  to  the directory containing the idfile is
	      required, as fetchmail writes a temporary file and renames it into the place of the
	      real  idfile  only if the temporary file has been written successfully. This avoids
	      the truncation of idfiles when running out of disk space.

       --pidfile <pathname>
	      (Keyword: pidfile; since fetchmail v6.3.4)
	      Override the default location of the PID file. Default: see "ENVIRONMENT" below.

       -n | --norewrite
	      (Keyword: no rewrite)
	      Normally, fetchmail edits RFC-822 address headers (To, From, Cc, Bcc, and Reply-To)
	      in  fetched  mail  so  that  any	mail IDs local to the server are expanded to full
	      addresses (@ and the mailserver hostname are appended).  This  enables  replies  on
	      the  client  to  get  addressed  correctly  (otherwise your mailer might think they
	      should be addressed to local users on the client machine!).  This  option  disables
	      the rewrite.  (This option is provided to pacify people who are paranoid about hav-
	      ing an MTA edit mail headers and want to know they can prevent it, but it is gener-
	      ally  not  a good idea to actually turn off rewrite.)  When using ETRN or ODMR, the
	      rewrite option is ineffective.

       -E <line> | --envelope <line>
	      (Keyword: envelope; Multidrop only)
	      In the configuration file, an enhanced syntax is used:
	      envelope [<count>] <line>

	      This option changes the header fetchmail assumes will carry a copy  of  the  mail's
	      envelope address.  Normally this is 'X-Envelope-To'.  Other typically found headers
	      to carry envelope information are 'X-Original-To' and 'Delivered-To'.   Now,  since
	      these  headers  are  not	standardized, practice varies. See the discussion of mul-
	      tidrop address handling below.  As a special case,  'envelope  "Received"'  enables
	      parsing  of  sendmail-style  Received  lines.  This is the default, but discouraged
	      because it is not fully reliable.

	      Note that fetchmail expects the Received-line to be in a specific format:  It  must
	      contain  "by  host  for address", where host must match one of the mailserver names
	      that fetchmail recognizes for the account in question.

	      The optional count argument (only available in the configuration	file)  determines
	      how many header lines of this kind are skipped. A count of 1 means: skip the first,
	      take the second. A count of 2 means: skip the first and second, take the third, and
	      so on.

       -Q <prefix> | --qvirtual <prefix>
	      (Keyword: qvirtual; Multidrop only)
	      The  string prefix assigned to this option will be removed from the user name found
	      in the header specified with the envelope option (before doing multidrop name  map-
	      ping  or	localdomain  checking, if either is applicable). This option is useful if
	      you are using fetchmail to collect the mail for an entire domain and your  ISP  (or
	      your mail redirection provider) is using qmail.  One of the basic features of qmail
	      is the Delivered-To: message header.  Whenever qmail delivers a message to a  local
	      mailbox  it  puts the username and hostname of the envelope recipient on this line.
	      The major reason for this is to prevent mail loops.  To set up qmail to batch  mail
	      for  a  disconnected  site the ISP-mailhost will have normally put that site in its
	      'Virtualhosts' control file so it will add a prefix to all mail addresses for  this
	      site.  This  results  in	mail sent to 'username@userhost.userdom.dom.com' having a
	      Delivered-To: line of the form:

	      Delivered-To: mbox-userstr-username@userhost.example.com

       The ISP can make the 'mbox-userstr-' prefix anything they choose but a string matching the
       user  host  name  is  likely.   By  using the option 'envelope Delivered-To:' you can make
       fetchmail reliably identify the original envelope recipient, but you  have  to  strip  the
       'mbox-userstr-' prefix to deliver to the correct user.  This is what this option is for.

       --configdump
	      Parse  the  ~/.fetchmailrc  file, interpret any command-line options specified, and
	      dump a configuration report to standard output.  The configuration report is a data
	      structure  assignment in the language Python.  This option is meant to be used with
	      an interactive ~/.fetchmailrc editor like fetchmailconf, written in Python.

   Removed Options
       -T | --netsec
	      Removed before version 6.3.0, the required underlying inet6_apps library	had  been
	      discontinued and is no longer available.

USER AUTHENTICATION AND ENCRYPTION
       All  modes  except  ETRN  require authentication of the client to the server.  Normal user
       authentication in fetchmail is very much like the authentication mechanism of ftp(1).  The
       correct user-id and password depend upon the underlying security system at the mailserver.

       If the mailserver is a Unix machine on which you have an ordinary user account, your regu-
       lar login name and password are used with fetchmail.  If you use the same  login  name  on
       both the server and the client machines, you needn't worry about specifying a user-id with
       the -u option -- the default behavior is to use your login name on the client  machine  as
       the  user-id  on  the  server  machine.	 If  you use a different login name on the server
       machine, specify that login name with the -u option.  e.g. if your login name is  'jsmith'
       on a machine named 'mailgrunt', you would start fetchmail as follows:

	      fetchmail -u jsmith mailgrunt

       The default behavior of fetchmail is to prompt you for your mailserver password before the
       connection is established.  This is the safest way to use fetchmail and ensures that  your
       password  will  not  be compromised.  You may also specify your password in your ~/.fetch-
       mailrc file.  This is convenient when using fetchmail in daemon mode or with scripts.

   Using netrc files
       If you do not specify a password, and fetchmail cannot extract  one  from  your	~/.fetch-
       mailrc file, it will look for a ~/.netrc file in your home directory before requesting one
       interactively; if an entry matching the mailserver is found in  that  file,  the  password
       will be used.  Fetchmail first looks for a match on poll name; if it finds none, it checks
       for a match on via name.  See the ftp(1) man  page  for	details  of  the  syntax  of  the
       ~/.netrc file.  To show a practical example, a .netrc might look like this:

	      machine hermes.example.org
	      login joe
	      password topsecret

       You can repeat this block with different user information if you need to provide more than
       one password.

       This feature may allow you to avoid duplicating password  information  in  more	than  one
       file.

       On  mailservers	that do not provide ordinary user accounts, your user-id and password are
       usually assigned by the server administrator when you apply for a mailbox on  the  server.
       Contact	your  server administrator if you don't know the correct user-id and password for
       your mailbox account.

POP3 VARIANTS
       Early versions of POP3 (RFC1081, RFC1225) supported a crude form of independent	authenti-
       cation  using  the  .rhosts file on the mailserver side.  Under this RPOP variant, a fixed
       per-user ID equivalent to a password was sent in clear over a link  to  a  reserved  port,
       with  the  command  RPOP  rather  than  PASS to alert the server that it should do special
       checking.  RPOP is supported by fetchmail (you can specify 'protocol  RPOP'  to	have  the
       program	send  'RPOP' rather than 'PASS') but its use is strongly discouraged, and support
       will be removed from a future fetchmail version.  This facility was vulnerable to spoofing
       and was withdrawn in RFC1460.

       RFC1460	introduced  APOP  authentication.   In this variant of POP3, you register an APOP
       password on your server	host  (on  some  servers,  the	program  to  do  this  is  called
       popauth(8)).   You put the same password in your ~/.fetchmailrc file.  Each time fetchmail
       logs in, it sends an MD5 hash of your password and the server greeting time to the server,
       which can verify it by checking its authorization database.

       Note that APOP is no longer considered resistant against man-in-the-middle attacks.

   RETR or TOP
       fetchmail  makes  some efforts to make the server believe messages had not been retrieved,
       by using the TOP command with a large number of lines when possible.   TOP  is  a  command
       that  retrieves	the  full  header  and	a fetchmail-specified amount of body lines. It is
       optional and therefore not implemented by all servers, and some are known to implement  it
       improperly.  On	many  servers  however, the RETR command which retrieves the full message
       with header and body, sets the "seen" flag (for instance, in a web interface), whereas the
       TOP command does not do that.

       fetchmail  will always use the RETR command if "fetchall" is set.  fetchmail will also use
       the RETR command if "keep" is set and "uidl" is unset.  Finally, fetchmail  will  use  the
       RETR command on Maillennium POP3/PROXY servers (used by Comcast) to avoid a deliberate TOP
       misinterpretation in this server that causes message corruption.

       In all other cases, fetchmail will use the TOP command. This implies that in  "keep"  set-
       ups, "uidl" must be set if "TOP" is desired.

       Note  that this description is true for the current version of fetchmail, but the behavior
       may change in future versions. In  particular,  fetchmail  may  prefer  the  RETR  command
       because the TOP command causes much grief on some servers and is only optional.

ALTERNATE AUTHENTICATION FORMS
       If  your fetchmail was built with Kerberos support and you specify Kerberos authentication
       (either with --auth or the .fetchmailrc option authenticate kerberos_v4) it  will  try  to
       get a Kerberos ticket from the mailserver at the start of each query.  Note: if either the
       pollname or via name is 'hesiod', fetchmail  will  try  to  use	Hesiod	to  look  up  the
       mailserver.

       If  you	use  POP3 or IMAP with GSSAPI authentication, fetchmail will expect the server to
       have RFC1731- or RFC1734-conforming GSSAPI capability, and will use  it.   Currently  this
       has only been tested over Kerberos V, so you're expected to already have a ticket-granting
       ticket. You may pass a username different from your  principal  name  using  the  standard
       --user command or by the .fetchmailrc option user.

       If  your  IMAP  daemon  returns	the PREAUTH response in its greeting line, fetchmail will
       notice this and skip the normal authentication step.  This can  be  useful,  e.g.  if  you
       start  imapd  explicitly using ssh.  In this case you can declare the authentication value
       'ssh' on that site entry to stop .fetchmail from asking you for a password when it  starts
       up.

       If  you use client authentication with TLS1 and your IMAP daemon returns the AUTH=EXTERNAL
       response, fetchmail will notice this and will use the authentication shortcut and will not
       send the passphrase. In this case you can declare the authentication value 'external'
	on that site to stop fetchmail from asking you for a password when it starts up.

       If  you	are using POP3, and the server issues a one-time-password challenge conforming to
       RFC1938, fetchmail will use your password as  a	pass  phrase  to  generate  the  required
       response. This avoids sending secrets over the net unencrypted.

       Compuserve's  RPA  authentication  is  supported. If you compile in the support, fetchmail
       will try to perform an RPA pass-phrase authentication instead of sending over the password
       en clair if it detects "@compuserve.com" in the hostname.

       If  you	are  using  IMAP, Microsoft's NTLM authentication (used by Microsoft Exchange) is
       supported. If you compile in the support, fetchmail will try to perform an NTLM	authenti-
       cation  (instead  of  sending  over  the  password  en  clair) whenever the server returns
       AUTH=NTLM in its capability  response.  Specify	a  user  option  value	that  looks  like
       'user@domain':  the  part to the left of the @ will be passed as the username and the part
       to the right as the NTLM domain.

   Secure Socket Layers (SSL) and Transport Layer Security (TLS)
       Note that fetchmail currently uses the OpenSSL library, which is severely underdocumented,
       so  failures may occur just because the programmers are not aware of OpenSSL's requirement
       of the day.  For instance, since v6.3.16,  fetchmail  calls  OpenSSL_add_all_algorithms(),
       which  is  necessary to support certificates with SHA256 on OpenSSL 0.9.8 -- this informa-
       tion is deeply hidden in the documentation and not at all obvious.  Please do not hesitate
       to report subtle SSL failures.

       You  can  access  SSL  encrypted services by specifying the --ssl option.  You can also do
       this using the "ssl" user option in the .fetchmailrc file. With	SSL  encryption  enabled,
       queries	are initiated over a connection after negotiating an SSL session, and the connec-
       tion fails if SSL cannot be negotiated.	Some services, such as POP3 and IMAP,  have  dif-
       ferent  well known ports defined for the SSL encrypted services.  The encrypted ports will
       be selected automatically when SSL is enabled and  no  explicit	port  is  specified.  The
       --sslproto 'SSL3' option should be used to select the SSLv3 protocol (default if unset: v2
       or v3).	Also, the --sslcertck command line or sslcertck run control file option should be
       used to force strict certificate checking - see below.

       If  SSL	is  not configured, fetchmail will usually opportunistically try to use STARTTLS.
       STARTTLS can be enforced by using --sslproto "TLS1". TLS connections use the same port  as
       the  unencrypted  version  of  the  protocol  and  negotiate  TLS via special command. The
       --sslcertck command line or sslcertck run control file option  should  be  used	to  force
       strict certificate checking - see below.

       --sslcertck  is recommended: When connecting to an SSL or TLS encrypted server, the server
       presents a certificate to the client for validation.  The certificate is checked to verify
       that the common name in the certificate matches the name of the server being contacted and
       that the effective and expiration dates in the certificate indicate that it  is	currently
       valid.  If any of these checks fail, a warning message is printed, but the connection con-
       tinues.	The server certificate does not need to be  signed  by	any  specific  Certifying
       Authority  and  may be a "self-signed" certificate. If the --sslcertck command line option
       or sslcertck run control file option is used, fetchmail will instead abort if any of these
       checks  fail, because it must assume that there is a man-in-the-middle attack in this sce-
       nario, hence fetchmail must not expose  cleartext  passwords.  Use  of  the  sslcertck  or
       --sslcertck option is therefore advised.

       Some  SSL  encrypted  servers may request a client side certificate.  A client side public
       SSL certificate and private SSL key may be specified.  If requested  by	the  server,  the
       client certificate is sent to the server for validation.  Some servers may require a valid
       client certificate and may refuse connections if a certificate is not provided or  if  the
       certificate  is not valid.  Some servers may require client side certificates be signed by
       a recognized Certifying Authority.  The format for the key files and the certificate files
       is that required by the underlying SSL libraries (OpenSSL in the general case).

       A  word	of care about the use of SSL: While above mentioned setup with self-signed server
       certificates retrieved over the wires can protect you  from  a  passive	eavesdropper,  it
       doesn't	help  against  an  active  attacker. It's clearly an improvement over sending the
       passwords in clear, but you should be aware that a man-in-the-middle attack  is	trivially
       possible (in particular with tools such as dsniff <http://monkey.org/~dugsong/dsniff/>, ).
       Use of strict certificate checking with a certification authority recognized by server and
       client,	or  perhaps  of  an SSH tunnel (see below for some examples) is preferable if you
       care seriously about the security of your mailbox and passwords.

   ESMTP AUTH
       fetchmail also supports authentication to the ESMTP server on the client side according to
       RFC  2554.   You can specify a name/password pair to be used with the keywords 'esmtpname'
       and 'esmtppassword'; the former defaults to the username of the calling user.

DAEMON MODE
   Introducing the daemon mode
       In daemon mode, fetchmail puts itself into the background and runs forever, querying  each
       specified host and then sleeping for a given polling interval.

   Starting the daemon mode
       There  are several ways to make fetchmail work in daemon mode. On the command line, --dae-
       mon <interval> or -d <interval> option runs fetchmail in daemon mode.  You must specify	a
       numeric	argument  which is a polling interval (time to wait after completing a whole poll
       cycle with the last server and before starting the next poll cycle with the first  server)
       in seconds.

       Example: simply invoking

	      fetchmail -d 900

       will,  therefore,  poll	all the hosts described in your ~/.fetchmailrc file (except those
       explicitly excluded with the 'skip' verb) a bit less often  than  once  every  15  minutes
       (exactly: 15 minutes + time that the poll takes).

       It  is  also  possible  to  set	a  polling interval in your ~/.fetchmailrc file by saying
       'set daemon <interval>', where <interval> is an integer number  of  seconds.   If  you  do
       this,  fetchmail will always start in daemon mode unless you override it with the command-
       line option --daemon 0 or -d0.

       Only one daemon process is permitted per user; in daemon mode, fetchmail sets  up  a  per-
       user  lockfile  to guarantee this.  (You can however cheat and set the FETCHMAILHOME envi-
       ronment variable to overcome this setting, but in that case, it is your responsibility  to
       make sure you aren't polling the same server with two processes at the same time.)

   Awakening the background daemon
       Normally,  calling fetchmail with a daemon in the background sends a wake-up signal to the
       daemon and quits without output. The background daemon then starts  its	next  poll  cycle
       immediately.   The  wake-up signal, SIGUSR1, can also be sent manually. The wake-up action
       also clears any 'wedged' flags indicating that  connections  have  wedged  due  to  failed
       authentication or multiple timeouts.

   Terminating the background daemon
       The  option --quit will kill a running daemon process instead of waking it up (if there is
       no such process, fetchmail will notify you).  If the --quit option  appears  last  on  the
       command	line,  fetchmail  will	kill the running daemon process and then quit. Otherwise,
       fetchmail will first kill a running daemon process and  then  continue  running	with  the
       other options.

   Useful options for daemon mode
       The  -L <filename> or --logfile <filename> option (keyword: set logfile) is only effective
       when fetchmail is detached and in daemon mode. Note that the  logfile  must  exist  before
       fetchmail  is run, you can use the touch(1) command with the filename as its sole argument
       to create it.
       This option allows you to redirect status messages into a specified  logfile  (follow  the
       option  with  the  logfile  name).  The logfile is opened for append, so previous messages
       aren't deleted.	This is primarily useful for debugging configurations. Note  that  fetch-
       mail  does  not	detect	if  the  logfile is rotated, the logfile is only opened once when
       fetchmail starts. You need to restart fetchmail after rotating the logfile and before com-
       pressing it (if applicable).

       The --syslog option (keyword: set syslog) allows you to redirect status and error messages
       emitted to the syslog(3) system daemon if available.  Messages are logged with  an  id  of
       fetchmail,  the	facility  LOG_MAIL,  and priorities LOG_ERR, LOG_ALERT or LOG_INFO.  This
       option is intended for logging status and error messages which indicate the status of  the
       daemon and the results while fetching mail from the server(s).  Error messages for command
       line options and parsing the .fetchmailrc file are still written  to  stderr,  or  to  the
       specified  log  file.   The  --nosyslog	option	turns off use of syslog(3), assuming it's
       turned on in the ~/.fetchmailrc file.  This option is overridden, in  certain  situations,
       by --logfile (which see).

       The  -N or --nodetach option suppresses backgrounding and detachment of the daemon process
       from its control terminal.  This is useful for debugging or when  fetchmail  runs  as  the
       child  of  a supervisor process such as init(8) or Gerrit Pape's runit(8).  Note that this
       also causes the logfile option to be ignored.

       Note that while running in daemon mode polling a POP2 or IMAP2bis server, transient errors
       (such  as DNS failures or sendmail delivery refusals) may force the fetchall option on for
       the duration of the next polling cycle.	This is a robustness feature.  It means that if a
       message	is fetched (and thus marked seen by the mailserver) but not delivered locally due
       to some transient error, it will be re-fetched during the  next	poll  cycle.   (The  IMAP
       logic doesn't delete messages until they're delivered, so this problem does not arise.)

       If  you touch or change the ~/.fetchmailrc file while fetchmail is running in daemon mode,
       this will be detected at the beginning of the next poll cycle.  When a  changed	~/.fetch-
       mailrc  is  detected,  fetchmail  rereads  it and restarts from scratch (using exec(2); no
       state information is retained in the new instance).  Note that if fetchmail needs to query
       for  passwords,	of  that  if you break the ~/.fetchmailrc file's syntax, the new instance
       will softly and silently vanish away on startup.

ADMINISTRATIVE OPTIONS
       The --postmaster <name> option (keyword: set postmaster) specifies the  last-resort  user-
       name  to  which	multidrop  mail  is to be forwarded if no matching local recipient can be
       found. It is also used as destination of undeliverable mail  if	the  'bouncemail'  global
       option  is off and additionally for spam-blocked mail if the 'bouncemail' global option is
       off and the 'spambounce' global option is on. This option defaults to the user who invoked
       fetchmail.   If	the  invoking  user  is root, then the default of this option is the user
       'postmaster'.  Setting postmaster to the empty string causes such mail as described  above
       to  be  discarded  -  this however is usually a bad idea.  See also the description of the
       'FETCHMAILUSER' environment variable in the ENVIRONMENT section below.

       The --nobounce behaves like the "set no bouncemail" global option, which see.

       The --invisible option (keyword: set invisible) tries to make fetchmail	invisible.   Nor-
       mally,  fetchmail  behaves like any other MTA would -- it generates a Received header into
       each message describing its place in the chain of transmission, and tells the MTA it  for-
       wards  to  that	the  mail  came  from the machine fetchmail itself is running on.  If the
       invisible option is on, the Received header is suppressed and fetchmail tries to spoof the
       MTA it forwards to into thinking it came directly from the mailserver host.

       The  --showdots option (keyword: set showdots) forces fetchmail to show progress dots even
       if the output goes to a file or fetchmail is not in verbose  mode.   Fetchmail  shows  the
       dots  by  default  when	run  in --verbose mode and output goes to console. This option is
       ignored in --silent mode.

       By specifying the --tracepolls option, you can ask fetchmail to	add  information  to  the
       Received header on the form "polling {label} account {user}", where {label} is the account
       label (from the specified rcfile, normally ~/.fetchmailrc)  and	{user}	is  the  username
       which  is  used	to  log  on to the mail server. This header can be used to make filtering
       email where no useful header information is available and you  want  mail  from	different
       accounts  sorted  into  different mailboxes (this could, for example, occur if you have an
       account on the same server running a mailing list, and are subscribed to  the  list  using
       that account). The default is not adding any such header.  In .fetchmailrc, this is called
       'tracepolls'.

RETRIEVAL FAILURE MODES
       The protocols fetchmail uses to talk to mailservers are next to	bulletproof.   In  normal
       operation  forwarding to port 25, no message is ever deleted (or even marked for deletion)
       on the host until the SMTP listener on the client side has acknowledged to fetchmail  that
       the message has been either accepted for delivery or rejected due to a spam block.

       When  forwarding  to  an  MDA, however, there is more possibility of error.  Some MDAs are
       'safe' and reliably return a nonzero status on any delivery error, even one due to  tempo-
       rary resource limits.  The maildrop(1) program is like this; so are most programs designed
       as mail transport agents, such as sendmail(1), including the sendmail wrapper  of  Postfix
       and exim(1).  These programs give back a reliable positive acknowledgement and can be used
       with the mda option with no risk of mail loss.  Unsafe MDAs, though, may return 0 even  on
       delivery failure.  If this happens, you will lose mail.

       The  normal mode of fetchmail is to try to download only 'new' messages, leaving untouched
       (and undeleted) messages you have already read directly on the server (or fetched  with	a
       previous  fetchmail  --keep).   But  you may find that messages you've already read on the
       server are being fetched (and deleted) even when you don't specify --all.  There are  sev-
       eral reasons this can happen.

       One  could  be  that  you're  using POP2.  The POP2 protocol includes no representation of
       'new' or 'old' state in messages, so fetchmail must treat all  messages	as  new  all  the
       time.  But POP2 is obsolete, so this is unlikely.

       A  potential POP3 problem might be servers that insert messages in the middle of mailboxes
       (some VMS implementations of mail are rumored to do this).   The  fetchmail  code  assumes
       that  new  messages  are  appended to the end of the mailbox; when this is not true it may
       treat some old messages as new and vice versa.  Using UIDL whilst setting fastuidl 0 might
       fix this, otherwise, consider switching to IMAP.

       Yet  another  POP3  problem is that if they can't make tempfiles in the user's home direc-
       tory, some POP3 servers will hand back an undocumented response that causes  fetchmail  to
       spuriously report "No mail".

       The  IMAP  code uses the presence or absence of the server flag \Seen to decide whether or
       not a message is new.  This isn't the right thing to do, fetchmail should check the UIDVA-
       LIDITY  and use UID, but it doesn't do that yet. Under Unix, it counts on your IMAP server
       to notice the BSD-style Status flags set by mail user agents and set the \Seen  flag  from
       them  when  appropriate.  All Unix IMAP servers we know of do this, though it's not speci-
       fied by the IMAP RFCs.  If you ever trip over a server that doesn't, the symptom  will  be
       that  messages  you  have  already read on your host will look new to the server.  In this
       (unlikely) case, only messages you fetched with fetchmail --keep will  be  both	undeleted
       and marked old.

       In  ETRN  and  ODMR modes, fetchmail does not actually retrieve messages; instead, it asks
       the server's SMTP listener to start a queue flush to the client via  SMTP.   Therefore  it
       sends only undelivered messages.

SPAM FILTERING
       Many  SMTP  listeners allow administrators to set up 'spam filters' that block unsolicited
       email from specified domains.  A MAIL FROM or DATA line that triggers  this  feature  will
       elicit an SMTP response which (unfortunately) varies according to the listener.

       Newer versions of sendmail return an error code of 571.

       According  to  RFC2821,	the  correct  thing to return in this situation is 550 "Requested
       action not taken: mailbox unavailable" (the draft  adds	"[E.g.,  mailbox  not  found,  no
       access, or command rejected for policy reasons].").

       Older versions of the exim MTA return 501 "Syntax error in parameters or arguments".

       The postfix MTA runs 554 as an antispam response.

       Zmailer may reject code with a 500 response (followed by an enhanced status code that con-
       tains more information).

       Return codes which fetchmail treats as antispam responses and discards the message can  be
       set  with  the  'antispam' option.  This is one of the only three circumstance under which
       fetchmail ever discards mail (the others are the 552 and 553 errors described  below,  and
       the suppression of multidropped messages with a message-ID already seen).

       If  fetchmail  is fetching from an IMAP server, the antispam response will be detected and
       the message rejected immediately after the headers have been fetched, without reading  the
       message body.  Thus, you won't pay for downloading spam message bodies.

       By default, the list of antispam responses is empty.

       If   the   spambounce  global  option  is  on,  mail  that  is  spam-blocked  triggers  an
       RFC1892/RFC1894 bounce message informing the originator that we do not  accept  mail  from
       it. See also BUGS.

SMTP/ESMTP ERROR HANDLING
       Besides	the spam-blocking described above, fetchmail takes special actions on the follow-
       ing SMTP/ESMTP error responses

       452 (insufficient system storage)
	    Leave the message in the server mailbox for later retrieval.

       552 (message exceeds fixed maximum message size)
	    Delete the message from the server.  Send bounce-mail to the originator.

       553 (invalid sending domain)
	    Delete the message from the server.  Don't even try to send bounce-mail to the origi-
	    nator.

       Other errors trigger bounce mail back to the originator. See also BUGS.

THE RUN CONTROL FILE
       The  preferred way to set up fetchmail is to write a .fetchmailrc file in your home direc-
       tory (you may do this directly, with a text  editor,  or  indirectly  via  fetchmailconf).
       When  there  is	a  conflict  between the command-line arguments and the arguments in this
       file, the command-line arguments take precedence.

       To protect the security of your passwords, your ~/.fetchmailrc may not normally have  more
       than  0700  (u=rwx,g=,o=)  permissions;	fetchmail  will complain and exit otherwise (this
       check is suppressed when --version is on).

       You may read the .fetchmailrc file as a list of commands to be executed when fetchmail  is
       called with no arguments.

   Run Control Syntax
       Comments begin with a '#' and extend through the end of the line.  Otherwise the file con-
       sists of a series of server entries or global option statements in a  free-format,  token-
       oriented syntax.

       There  are four kinds of tokens: grammar keywords, numbers (i.e. decimal digit sequences),
       unquoted strings, and quoted strings.  A quoted string is bounded by double quotes and may
       contain	whitespace (and quoted digits are treated as a string).  Note that quoted strings
       will also contain line feed characters if they run across two or more  lines,  unless  you
       use a backslash to join lines (see below).  An unquoted string is any whitespace-delimited
       token that is neither numeric, string quoted nor contains the special characters ',', ';',
       ':', or '='.

       Any amount of whitespace separates tokens in server entries, but is otherwise ignored. You
       may use backslash escape sequences (\n for LF, \t for HT, \b for BS, \r for CR,	\nnn  for
       decimal	(where	nnn  cannot  start with a 0), \0ooo for octal, and \xhh for hex) to embed
       non-printable characters or string delimiters in strings.  In quoted strings, a	backslash
       at the very end of a line will cause the backslash itself and the line feed (LF or NL, new
       line) character to be ignored, so that you can wrap long strings. Without the backslash at
       the line end, the line feed character would become part of the string.

       Warning:  while these resemble C-style escape sequences, they are not the same.	fetchmail
       only supports these eight styles. C supports more escape sequences that consist	of  back-
       slash  (\) and a single character, but does not support decimal codes and does not require
       the leading 0 in octal notation.  Example: fetchmail interprets	\233  the  same  as  \xE9
       (Latin small letter e with acute), where C would interpret \233 as octal 0233 = \x9B (CSI,
       control sequence introducer).

       Each server entry consists of one of the keywords 'poll' or 'skip', followed by	a  server
       name,  followed	by  server options, followed by any number of user (or username) descrip-
       tions, followed by user options.  Note: the most common cause of syntax errors  is  mixing
       up user and server options or putting user options before the user descriptions.

       For backward compatibility, the word 'server' is a synonym for 'poll'.

       You can use the noise keywords 'and', 'with', 'has', 'wants', and 'options' anywhere in an
       entry to make it resemble English.  They're ignored, but but can make entries much  easier
       to read at a glance.  The punctuation characters ':', ';' and ',' are also ignored.

   Poll vs. Skip
       The  'poll' verb tells fetchmail to query this host when it is run with no arguments.  The
       'skip' verb tells fetchmail not to poll this host unless it is  explicitly  named  on  the
       command line.  (The 'skip' verb allows you to experiment with test entries safely, or eas-
       ily disable entries for hosts that are temporarily down.)

   Keyword/Option Summary
       Here are the legal options.  Keyword suffixes enclosed in square  brackets  are	optional.
       Those  corresponding to short command-line options are followed by '-' and the appropriate
       option letter.  If option is only relevant to a single mode of operation, it is	noted  as
       's' or 'm' for singledrop- or multidrop-mode, respectively.

       Here are the legal global options:

       Keyword		   Opt	 Mode	Function
       --------------------------------------------------------------------
       set daemon	   -d		Set  a background poll interval in
					seconds.
       set postmaster			Give the name of  the  last-resort
					mail recipient (default: user run-
					ning  fetchmail,  "postmaster"	if
					run by the root user)

       set    bouncemail		Direct	error  mail  to the sender
					(default)
       set no bouncemail		Direct error  mail  to	the  local
					postmaster  (as  per the 'postmas-
					ter' global option above).
       set no spambounce		Do not	bounce	spam-blocked  mail
					(default).
       set    spambounce		Bounce	blocked  spam-blocked mail
					(as  per   the	 'antispam'   user
					option) back to the destination as
					indicated  by	the   'bouncemail'
					global	option.   Warning:  Do not
					use this to bounce  spam  back	to
					the  sender  -	most  spam is sent
					with false sender address and thus
					this	option	  hurts   innocent
					bystanders.
       set no softbounce		Delete	permanently  undeliverable
					mail.  It  is  recommended  to use
					this option if	the  configuration
					has been thoroughly tested.
       set    softbounce		Keep   permanently   undeliverable
					mail as though a  temporary  error
					had occurred (default).
       set logfile	   -L		Name of a file to append error and
					status messages to.   Only  effec-
					tive  in daemon mode and if fetch-
					mail  detaches.    If	effective,
					overrides set syslog.
       set idfile	   -i		Name  of  the  file  to  store UID
					lists in.
       set    syslog			Do  error  logging  through   sys-
					log(3).  May  be  overriden by set
					logfile.
       set no syslog			Turn  off  error  logging  through
					syslog(3). (default)
       set properties			String	value  that  is ignored by
					fetchmail (may be used	by  exten-
					sion scripts).

       Here are the legal server options:

       Keyword		Opt   Mode   Function
       -----------------------------------------------------------------
       via			     Specify  DNS  name  of mailserver,
				     overriding poll name
       proto[col]	-p	     Specify  protocol	(case  insensi-
				     tive):  POP2,  POP3,  IMAP,  APOP,
				     KPOP
       local[domains]	      m      Specify domain(s) to  be  regarded
				     as local
       port			     Specify TCP/IP service port (obso-
				     lete, use 'service' instead).
       service		-P	     Specify service  name  (a	numeric
				     value  is also allowed and consid-
				     ered a TCP/IP port number).
       auth[enticate]		     Set authentication  type  (default
				     'any')
       timeout		-t	     Server  inactivity timeout in sec-
				     onds (default 300)
       envelope 	-E    m      Specify  envelope-address	 header
				     name
       no envelope	      m      Disable   looking	 for   envelope
				     address
       qvirtual 	-Q    m      Qmail  virtual  domain  prefix  to
				     remove from user name
       aka		      m      Specify  alternate  DNS  names  of
				     mailserver
       interface	-I	     specify IP interface(s) that  must
				     be  up  for  server  poll	to take
				     place

       monitor		-M	     Specify IP address to monitor  for
				     activity
       plugin			     Specify  command  through which to
				     make server connections.
       plugout			     Specify command through  which  to
				     make listener connections.
       dns		      m      Enable  DNS  lookup  for multidrop
				     (default)
       no dns		      m      Disable DNS lookup for multidrop
       checkalias	      m      Do comparison by  IP  address  for
				     multidrop
       no checkalias	      m      Do  comparison  by  name  for mul-
				     tidrop (default)
       uidl		-U	     Force  POP3  to  use   client-side
				     UIDLs (recommended)
       no uidl			     Turn  off	POP3 use of client-side
				     UIDLs (default)
       interval 		     Only check this site every N  poll
				     cycles; N is a numeric argument.
       tracepolls		     Add  poll	tracing  information to
				     the Received header
       principal		     Set Kerberos principal (only  use-
				     ful with IMAP and kerberos)
       esmtpname		     Set  name	for RFC2554 authentica-
				     tion to the ESMTP server.
       esmtppassword		     Set password for RFC2554 authenti-
				     cation to the ESMTP server.
       bad-header		     How  to  treat messages with a bad
				     header. Can be reject (default) or
				     accept.

       Here are the legal user descriptions and options:

       Keyword		  Opt	Mode   Function
       -------------------------------------------------------------------
       user[name]	  -u	       This  is  the user description and
				       must  come  first   after   server
				       description   and  after  possible
				       server options,	and  before  user
				       options.
				       It sets the remote user name if by
				       itself or followed by 'there',  or
				       the local user name if followed by
				       'here'.
       is			       Connect	local  and  remote   user
				       names
       to			       Connect	 local	and  remote  user
				       names
       pass[word]		       Specify remote account password
       ssl			       Connect to server over the  speci-
				       fied   base   protocol  using  SSL
				       encryption
       sslcert			       Specify file for client side  pub-
				       lic SSL certificate
       sslcertfile		       Specify	file with trusted CA cer-
				       tificates
       sslcertpath		       Specify c_rehash-ed directory with
				       trusted CA certificates.
       sslkey			       Specify	file for client side pri-
				       vate SSL key
       sslproto 		       Force ssl protocol for connection
       folder		  -r	       Specify remote folder to query
       smtphost 	  -S	       Specify smtp host(s) to forward to
       fetchdomains		m      Specify	domains  for  which  mail
				       should be fetched
       smtpaddress	  -D	       Specify	the  domain  to be put in
				       RCPT TO lines
       smtpname 		       Specify the user and domain to  be
				       put in RCPT TO lines
       antispam 	  -Z	       Specify	 what  SMTP  returns  are
				       interpreted as spam-policy blocks

       mda		  -m	       Specify MDA for local delivery
       bsmtp		  -o	       Specify BSMTP batch file to append
				       to
       preconnect		       Command to be executed before each
				       connection
       postconnect		       Command to be executed after  each
				       connection
       keep		  -k	       Don't  delete  seen  messages from
				       server (for POP3, uidl  is  recom-
				       mended)
       flush		  -F	       Flush  all  seen  messages  before
				       querying (DANGEROUS)
       limitflush		       Flush   all   oversized	 messages
				       before querying
       fetchall 	  -a	       Fetch all messages whether seen or
				       not
       rewrite			       Rewrite destination addresses  for
				       reply (default)
       stripcr			       Strip  carriage	returns from ends
				       of lines
       forcecr			       Force carriage returns at ends  of
				       lines
       pass8bits		       Force  BODY=8BITMIME to ESMTP lis-
				       tener
       dropstatus		       Strip Status and  X-Mozilla-Status
				       lines out of incoming mail
       dropdelivered		       Strip  Delivered-To  lines  out of
				       incoming mail
       mimedecode		       Convert quoted-printable to  8-bit
				       in MIME messages
       idle			       Idle   waiting  for  new  messages
				       after each poll (IMAP only)
       no keep		  -K	       Delete seen messages  from  server
				       (default)
       no flush 		       Don't   flush  all  seen  messages
				       before querying (default)
       no fetchall		       Retrieve   only	  new	 messages
				       (default)
       no rewrite		       Don't rewrite headers
       no stripcr		       Don't   strip   carriage   returns
				       (default)
       no forcecr		       Don't force  carriage  returns  at
				       EOL (default)
       no pass8bits		       Don't force BODY=8BITMIME to ESMTP
				       listener (default)
       no dropstatus		       Don't	drop	Status	  headers
				       (default)
       no dropdelivered 	       Don't  drop  Delivered-To  headers
				       (default)
       no mimedecode		       Don't convert quoted-printable  to
				       8-bit in MIME messages (default)
       no idle			       Don't  idle  waiting  for new mes-
				       sages after each poll (IMAP only)
       limit		  -l	       Set message size limit
       warnings 	  -w	       Set message size warning interval
       batchlimit	  -b	       Max # messages to forward in  sin-
				       gle connect
       fetchlimit	  -B	       Max  # messages to fetch in single
				       connect
       fetchsizelimit		       Max # message sizes  to	fetch  in
				       single transaction
       fastuidl 		       Use binary search for first unseen
				       message (POP3 only)
       expunge		  -e	       Perform an expunge  on  every  #th
				       message (IMAP and POP3 only)
       properties		       String  value is ignored by fetch-
				       mail (may  be  used  by	extension
				       scripts)

       All  user  options must begin with a user description (user or username option) and follow
       all server descriptions and options.

       In the .fetchmailrc file, the 'envelope' string argument may be preceded by a  whitespace-
       separated  number.   This number, if specified, is the number of such headers to skip over
       (that is, an argument of 1 selects the second header of the given type).  This is sometime
       useful  for  ignoring  bogus  envelope headers created by an ISP's local delivery agent or
       internal forwards (through mail inspection systems, for instance).

   Keywords Not Corresponding To Option Switches
       The 'folder' and 'smtphost' options (unlike their command-line  equivalents)  can  take	a
       space- or comma-separated list of names following them.

       All options correspond to the obvious command-line arguments, except the following: 'via',
       'interval', 'aka', 'is', 'to', 'dns'/'no dns', 'checkalias'/'no	checkalias',  'password',
       'preconnect',   'postconnect',	'localdomains',   'stripcr'/'no  stripcr',  'forcecr'/'no
       forcecr', 'pass8bits'/'no pass8bits' 'dropstatus/no dropstatus', 'dropdelivered/no dropde-
       livered', 'mimedecode/no mimedecode', 'no idle', and 'no envelope'.

       The  'via'  option  is for if you want to have more than one configuration pointing at the
       same site.  If it is present, the string argument will be taken as the actual DNS name  of
       the  mailserver	host  to  query.  This will override the argument of poll, which can then
       simply be a distinct label for the configuration (e.g. what you would give on the  command
       line to explicitly query this host).

       The  'interval'	option	(which takes a numeric argument) allows you to poll a server less
       frequently than the basic poll interval.  If you say 'interval N' the server  this  option
       is attached to will only be queried every N poll intervals.

   Singledrop vs. Multidrop options
       Please  ensure you read the section titled THE USE AND ABUSE OF MULTIDROP MAILBOXES if you
       intend to use multidrop mode.

       The 'is' or 'to' keywords associate the following local (client) name(s)  (or  server-name
       to client-name mappings separated by =) with the mailserver user name in the entry.  If an
       is/to list has '*' as its last name, unrecognized names are simply  passed  through.  Note
       that until fetchmail version 6.3.4 inclusively, these lists could only contain local parts
       of user names (fetchmail would only look at the part before the @  sign).  fetchmail  ver-
       sions  6.3.5 and newer support full addresses on the left hand side of these mappings, and
       they take precedence over any 'localdomains', 'aka', 'via' or similar mappings.

       A single local name can be used to support redirecting your mail when your username on the
       client machine is different from your name on the mailserver.  When there is only a single
       local name, mail is forwarded to that local username regardless of the message's Received,
       To, Cc, and Bcc headers.  In this case, fetchmail never does DNS lookups.

       When  there is more than one local name (or name mapping), fetchmail looks at the envelope
       header, if configured, and otherwise at the Received, To, Cc, and Bcc headers of retrieved
       mail  (this  is	'multidrop mode').  It looks for addresses with hostname parts that match
       your poll name or your 'via', 'aka' or 'localdomains' options, and usually also for  host-
       name parts which DNS tells it are aliases of the mailserver.  See the discussion of 'dns',
       'checkalias', 'localdomains', and 'aka' for details on how matching addresses are handled.

       If fetchmail cannot match any mailserver usernames or localdomain addresses, the mail will
       be  bounced.   Normally	it  will be bounced to the sender, but if the 'bouncemail' global
       option is off, the mail will go to the local postmaster instead.   (see	the  'postmaster'
       global option). See also BUGS.

       The  'dns'  option  (normally  on) controls the way addresses from multidrop mailboxes are
       checked.  On, it enables logic to check each host address that does not match an 'aka'  or
       'localdomains'  declaration by looking it up with DNS.  When a mailserver username is rec-
       ognized attached to a matching hostname part, its local mapping is added to  the  list  of
       local recipients.

       The  'checkalias' option (normally off) extends the lookups performed by the 'dns' keyword
       in multidrop mode, providing a way to cope with remote MTAs that identify themselves using
       their  canonical name, while they're polled using an alias.  When such a server is polled,
       checks to extract the envelope address fail, and fetchmail reverts to delivery  using  the
       To/Cc/Bcc  headers  (See  below	'Header vs. Envelope addresses').  Specifying this option
       instructs fetchmail to retrieve all the IP addresses associated with both  the  poll  name
       and  the  name  used  by  the remote MTA and to do a comparison of the IP addresses.  This
       comes in handy in situations where the remote server  undergoes	frequent  canonical  name
       changes,  that  would  otherwise require modifications to the rcfile.  'checkalias' has no
       effect if 'no dns' is specified in the rcfile.

       The 'aka' option is for use with multidrop mailboxes.  It allows you to pre-declare a list
       of  DNS aliases for a server.  This is an optimization hack that allows you to trade space
       for speed.  When fetchmail, while processing a multidrop mailbox, grovels through  message
       headers	looking  for  names of the mailserver, pre-declaring common ones can save it from
       having to do DNS lookups.  Note: the names you give as arguments to 'aka' are  matched  as
       suffixes  --  if  you  specify (say) 'aka netaxs.com', this will match not just a hostname
       netaxs.com, but any hostname that ends with '.netaxs.com'; such as  (say)  pop3.netaxs.com
       and mail.netaxs.com.

       The  'localdomains'  option allows you to declare a list of domains which fetchmail should
       consider local.	When fetchmail is parsing address lines in multidrop modes, and a  trail-
       ing segment of a host name matches a declared local domain, that address is passed through
       to the listener or MDA unaltered (local-name mappings are not applied).

       If you are using 'localdomains', you may also need to specify 'no  envelope',  which  dis-
       ables  fetchmail's  normal attempt to deduce an envelope address from the Received line or
       X-Envelope-To header or whatever header has been previously set by 'envelope'.  If you set
       'no  envelope'  in the defaults entry it is possible to undo that in individual entries by
       using 'envelope <string>'.  As a special case, 'envelope "Received"' restores the  default
       parsing of Received lines.

       The  password option requires a string argument, which is the password to be used with the
       entry's server.

       The 'preconnect' keyword allows you to specify a shell command to be executed just  before
       each  time  fetchmail  establishes a mailserver connection.  This may be useful if you are
       attempting to set up secure POP connections with  the  aid  of  ssh(1).	 If  the  command
       returns a nonzero status, the poll of that mailserver will be aborted.

       Similarly, the 'postconnect' keyword similarly allows you to specify a shell command to be
       executed just after each time a mailserver connection is taken down.

       The 'forcecr' option controls whether lines terminated by LF only are given CRLF  termina-
       tion  before forwarding.  Strictly speaking RFC821 requires this, but few MTAs enforce the
       requirement it so this option is normally off (only one such MTA, qmail, is in significant
       use at time of writing).

       The  'stripcr' option controls whether carriage returns are stripped out of retrieved mail
       before it is forwarded.	It is normally not necessary to set this, because it defaults  to
       'on'  (CR  stripping  enabled)  when there is an MDA declared but 'off' (CR stripping dis-
       abled) when forwarding is via SMTP.  If 'stripcr' and 'forcecr'	are  both  on,	'stripcr'
       will override.

       The  'pass8bits'  option  exists to cope with Microsoft mail programs that stupidly slap a
       "Content-Transfer-Encoding: 7bit" on everything.  With this option off (the  default)  and
       such  a	header	present,  fetchmail declares BODY=7BIT to an ESMTP-capable listener; this
       causes problems for messages actually using 8-bit ISO or KOI-8 character sets, which  will
       be  garbled  by	having	the  high bits of all characters stripped.  If 'pass8bits' is on,
       fetchmail is forced to declare BODY=8BITMIME to any ESMTP-capable listener.  If	the  lis-
       tener is 8-bit-clean (as all the major ones now are) the right thing will probably result.

       The  'dropstatus'  option  controls whether nonempty Status and X-Mozilla-Status lines are
       retained in fetched mail (the default) or discarded.  Retaining them allows  your  MUA  to
       see what messages (if any) were marked seen on the server.  On the other hand, it can con-
       fuse some new-mail notifiers, which assume that anything with a Status line in it has been
       seen.   (Note:  the empty Status lines inserted by some buggy POP servers are uncondition-
       ally discarded.)

       The 'dropdelivered' option controls whether Delivered-To headers will be kept  in  fetched
       mail  (the default) or discarded. These headers are added by Qmail and Postfix mailservers
       in order to avoid mail loops but may get in your way if you try to "mirror"  a  mailserver
       within the same domain. Use with caution.

       The 'mimedecode' option controls whether MIME messages using the quoted-printable encoding
       are automatically converted into pure 8-bit data. If you are delivering mail to an  ESMTP-
       capable,  8-bit-clean  listener	(that includes all of the major MTAs like sendmail), then
       this will automatically convert quoted-printable message headers and data into 8-bit data,
       making it easier to understand when reading mail. If your e-mail programs know how to deal
       with MIME messages, then this option is not needed.   The  mimedecode  option  is  off  by
       default, because doing RFC2047 conversion on headers throws away character-set information
       and can lead to bad results if the encoding of the headers differs from the body encoding.

       The 'idle' option is intended to be used with IMAP servers  supporting  the  RFC2177  IDLE
       command	extension,  but  does  not  strictly require it.  If it is enabled, and fetchmail
       detects that IDLE is supported, an IDLE will be issued at the end of each poll.	This will
       tell  the  IMAP	server to hold the connection open and notify the client when new mail is
       available.  If IDLE is not supported, fetchmail will simulate it by  periodically  issuing
       NOOP. If you need to poll a link frequently, IDLE can save bandwidth by eliminating TCP/IP
       connects and LOGIN/LOGOUT sequences. On the other hand, an IDLE connection will eat almost
       all  of	your  fetchmail's time, because it will never drop the connection and allow other
       polls to occur unless the server times out the IDLE.  It also doesn't work  with  multiple
       folders; only the first folder will ever be polled.

       The  'properties'  option is an extension mechanism.  It takes a string argument, which is
       ignored by fetchmail itself.  The string argument  may  be  used  to  store  configuration
       information  for  scripts  which  require it.  In particular, the output of '--configdump'
       option will make properties associated with a user entry readily  available  to	a  Python
       script.

   Miscellaneous Run Control Options
       The  words  'here' and 'there' have useful English-like significance.  Normally 'user eric
       is esr' would mean that mail for the remote user 'eric' is to be delivered to  'esr',  but
       you can make this clearer by saying 'user eric there is esr here', or reverse it by saying
       'user esr here is eric there'

       Legal protocol identifiers for use with the 'protocol' keyword are:

	   auto (or AUTO) (legacy, to be removed from future release)
	   pop2 (or POP2) (legacy, to be removed from future release)
	   pop3 (or POP3)
	   sdps (or SDPS)
	   imap (or IMAP)
	   apop (or APOP)
	   kpop (or KPOP)

       Legal authentication types are 'any', 'password', 'kerberos', 'kerberos_v4', 'kerberos_v5'
       and  'gssapi',  'cram-md5',  'otp', 'msn' (only for POP3), 'ntlm', 'ssh', 'external' (only
       IMAP).  The 'password' type specifies authentication by normal transmission of a  password
       (the  password  may  be	plain text or subject to protocol-specific encryption as in CRAM-
       MD5); 'kerberos' tells fetchmail to try to get a Kerberos ticket  at  the  start  of  each
       query  instead, and send an arbitrary string as the password; and 'gssapi' tells fetchmail
       to use GSSAPI authentication.  See the description of the 'auth' keyword for more.

       Specifying 'kpop' sets POP3 protocol over  port	1109  with  Kerberos  V4  authentication.
       These defaults may be overridden by later options.

       There  are some global option statements: 'set logfile' followed by a string sets the same
       global specified by --logfile.  A command-line --logfile option will override  this.  Note
       that  --logfile	is  only effective if fetchmail detaches itself from the terminal and the
       logfile already exists before fetchmail is run, and it overrides --syslog  in  this  case.
       Also,  'set  daemon' sets the poll interval as --daemon does.  This can be overridden by a
       command-line --daemon option; in particular --daemon 0 can be  used  to	force  foreground
       operation.  The	'set  postmaster'  statement  sets  the  address  to which multidrop mail
       defaults if there are no local matches.	Finally, 'set syslog' sends log messages to  sys-
       logd(8).

DEBUGGING FETCHMAIL
   Fetchmail crashing
       There  are  various  ways in that fetchmail may "crash", i. e. stop operation suddenly and
       unexpectedly. A "crash" usually refers to an error condition that  the  software  did  not
       handle  by itself. A well-known failure mode is the "segmentation fault" or "signal 11" or
       "SIGSEGV" or just "segfault" for short. These can be caused by  hardware  or  by  software
       problems.  Software-induced  segfaults  can  usually  be reproduced easily and in the same
       place, whereas hardware-induced segfaults can go away if the computer is rebooted, or pow-
       ered  off for a few hours, and can happen in random locations even if you use the software
       the same way.

       For solving hardware-induced segfaults, find the faulty component and  repair  or  replace
       it.  The Sig11 FAQ <http://www.bitwizard.nl/sig11/> may help you with details.

       For solving software-induced segfaults, the developers may need a "stack backtrace".

   Enabling fetchmail core dumps
       By  default,  fetchmail	suppresses  core dumps as these might contain passwords and other
       sensitive information. For debugging fetchmail crashes, obtaining a "stack backtrace" from
       a  core dump is often the quickest way to solve the problem, and when posting your problem
       on a mailing list, the developers may ask you for a "backtrace".

       1. To get useful backtraces, fetchmail needs to be installed without getting  stripped  of
       its  compilation  symbols.   Unfortunately,  most  binary  packages that are installed are
       stripped, and core files from symbol-stripped programs are worthless. So you may  need  to
       recompile fetchmail. On many systems, you can type

	       file `which fetchmail`

       to  find  out if fetchmail was symbol-stripped or not. If yours was unstripped, fine, pro-
       ceed, if it was stripped, you need to recompile the source code first. You do not  usually
       need to install fetchmail in order to debug it.

       2.  The shell environment that starts fetchmail needs to enable core dumps. The key is the
       "maximum core (file) size" that can usually be configured with a  tool  named  "limit"  or
       "ulimit".  See  the  documentation  for your shell for details. In the popular bash shell,
       "ulimit -Sc unlimited" will allow the core dump.

       3. You need to tell fetchmail, too, to allow core dumps. To do this,  run  fetchmail  with
       the -d0 -v options.  It is often easier to also add --nosyslog -N as well.

       Finally,  you need to reproduce the crash. You can just start fetchmail from the directory
       where you compiled it by typing ./fetchmail, so the complete command line will start  with
       ./fetchmail -Nvd0 --nosyslog and perhaps list your other options.

       After  the  crash,  run your debugger to obtain the core dump.  The debugger will often be
       GNU GDB, you can then type (adjust paths as necessary) gdb ./fetchmail fetchmail.core  and
       then,  after GDB has started up and read all its files, type backtrace full, save the out-
       put (copy & paste will do, the backtrace will be read by a human) and then  type  quit  to
       leave gdb.  Note: on some systems, the core files have different names, they might contain
       a number instead of the program name, or number and name, but it will usually have  "core"
       as part of their name.

INTERACTION WITH RFC 822
       When  trying  to  determine  the originating address of a message, fetchmail looks through
       headers in the following order:

	       Return-Path:
	       Resent-Sender: (ignored if it doesn't contain an @ or !)
	       Sender: (ignored if it doesn't contain an @ or !)
	       Resent-From:
	       From:
	       Reply-To:
	       Apparently-From:

       The originating address is used for logging, and to set the MAIL FROM  address  when  for-
       warding	to  SMTP.   This order is intended to cope gracefully with receiving mailing list
       messages in multidrop mode. The intent is that if  a  local  address  doesn't  exist,  the
       bounce  message	won't be returned blindly to the author or to the list itself, but rather
       to the list manager (which is less annoying).

       In multidrop mode, destination headers are processed as follows:  First,  fetchmail  looks
       for  the header specified by the 'envelope' option in order to determine the local recipi-
       ent address. If the mail is addressed to more than one recipient, the Received line  won't
       contain any information regarding recipient addresses.

       Then  fetchmail	looks  for  the  Resent-To:,  Resent-Cc:, and Resent-Bcc: lines.  If they
       exist,  they  should  contain  the  final  recipients  and  have  precedence  over   their
       To:/Cc:/Bcc:  counterparts.   If  the  Resent-*	lines don't exist, the To:, Cc:, Bcc: and
       Apparently-To: lines are looked for. (The presence of a Resent-To: is taken to imply  that
       the  person  referred  by  the  To:  address has already received the original copy of the
       mail.)

CONFIGURATION EXAMPLES
       Note that although there are password declarations in a good many of the  examples  below,
       this is mainly for illustrative purposes.  We recommend stashing account/password pairs in
       your $HOME/.netrc file, where they can be used not just by fetchmail  but  by  ftp(1)  and
       other programs.

       The basic format is:

	      poll SERVERNAME protocol PROTOCOL username NAME password PASSWORD

       Example:

	      poll pop.provider.net protocol pop3 username "jsmith" password "secret1"

       Or, using some abbreviations:

	      poll pop.provider.net proto pop3 user "jsmith" password "secret1"

       Multiple servers may be listed:

	      poll pop.provider.net proto pop3 user "jsmith" pass "secret1"
	      poll other.provider.net proto pop2 user "John.Smith" pass "My^Hat"

       Here's the same version with more whitespace and some noise words:

	      poll pop.provider.net proto pop3
		   user "jsmith", with password secret1, is "jsmith" here;
	      poll other.provider.net proto pop2:
		   user "John.Smith", with password "My^Hat", is "John.Smith" here;

       If you need to include whitespace in a parameter string or start the latter with a number,
       enclose the string in double quotes.  Thus:

	      poll mail.provider.net with proto pop3:
		   user "jsmith" there has password "4u but u can't krak this"
		   is jws here and wants mda "/bin/mail"

       You may have an initial server description headed by the  keyword  'defaults'  instead  of
       'poll'  followed  by  a name.  Such a record is interpreted as defaults for all queries to
       use. It may be overwritten by individual server descriptions.  So, you could write:

	      defaults proto pop3
		   user "jsmith"
	      poll pop.provider.net
		   pass "secret1"
	      poll mail.provider.net
		   user "jjsmith" there has password "secret2"

       It's possible to specify more than one user per server.	The 'user' keyword  leads  off	a
       user  description,  and	every  user  specification in a multi-user entry must include it.
       Here's an example:

	      poll pop.provider.net proto pop3 port 3111
		   user "jsmith" with pass "secret1" is "smith" here
		   user jones with pass "secret2" is "jjones" here keep

       This associates the local username 'smith' with the pop.provider.net username 'jsmith' and
       the  local username 'jjones' with the pop.provider.net username 'jones'.  Mail for 'jones'
       is kept on the server after download.

       Here's what a simple retrieval configuration for a multidrop mailbox looks like:

	      poll pop.provider.net:
		   user maildrop with pass secret1 to golux 'hurkle'='happy' snark here

       This says that the mailbox of account 'maildrop' on the server is  a  multidrop	box,  and
       that  messages  in  it  should  be parsed for the server user names 'golux', 'hurkle', and
       'snark'.  It further specifies that 'golux' and 'snark' have the same name on  the  client
       as  on  the  server,  but mail for server user 'hurkle' should be delivered to client user
       'happy'.

       Note that fetchmail, until version 6.3.4, did NOT allow	full  user@domain  specifications
       here,  these  would never match.  Fetchmail 6.3.5 and newer support user@domain specifica-
       tions on the left-hand side of a user mapping.

       Here's an example of another kind of multidrop connection:

	      poll pop.provider.net localdomains loonytoons.org toons.org
		   envelope X-Envelope-To
		   user maildrop with pass secret1 to * here

       This also says that the mailbox of account 'maildrop' on the server is  a  multidrop  box.
       It  tells fetchmail that any address in the loonytoons.org or toons.org domains (including
       sub-domain addresses like 'joe@daffy.loonytoons.org') should  be  passed  through  to  the
       local SMTP listener without modification.  Be careful of mail loops if you do this!

       Here's  an  example  configuration  using ssh and the plugin option.  The queries are made
       directly on the stdin and stdout of imapd via ssh.  Note that in this setup, IMAP  authen-
       tication can be skipped.

	      poll mailhost.net with proto imap:
		   plugin "ssh %h /usr/sbin/imapd" auth ssh;
		   user esr is esr here

THE USE AND ABUSE OF MULTIDROP MAILBOXES
       Use the multiple-local-recipients feature with caution -- it can bite.  All multidrop fea-
       tures are ineffective in ETRN and ODMR modes.

       Also, note that in multidrop mode duplicate mails are suppressed.  A piece of mail is con-
       sidered	duplicate  if it has the same message-ID as the message immediately preceding and
       more than one addressee.  Such runs of messages may be generated when copies of a  message
       addressed to multiple users are delivered to a multidrop box.

   Header vs. Envelope addresses
       The  fundamental problem is that by having your mailserver toss several peoples' mail in a
       single maildrop box, you may have thrown away potentially vital information about who each
       piece  of mail was actually addressed to (the 'envelope address', as opposed to the header
       addresses in the RFC822 To/Cc headers - the Bcc is not available at  the  receiving  end).
       This 'envelope address' is the address you need in order to reroute mail properly.

       Sometimes  fetchmail  can  deduce the envelope address.	If the mailserver MTA is sendmail
       and the item of mail had just one recipient, the MTA will have written a  'by/for'  clause
       that gives the envelope addressee into its Received header. But this doesn't work reliably
       for other MTAs, nor if there is more than one recipient.  By default, fetchmail looks  for
       envelope  addresses  in	these  lines;  you can restore this default with -E "Received" or
       'envelope Received'.

       As a better alternative, some SMTP listeners and/or mail servers insert a header  in  each
       message	containing  a  copy  of  the envelope addresses.  This header (when it exists) is
       often 'X-Original-To', 'Delivered-To' or 'X-Envelope-To'.   Fetchmail's	assumption  about
       this  can  be  changed  with  the  -E or 'envelope' option.  Note that writing an envelope
       header of this kind exposes the names of recipients (including blind-copy  recipients)  to
       all  receivers  of  the	messages,  so the upstream must store one copy of the message per
       recipient to avoid becoming a privacy problem.

       Postfix, since version 2.0, writes an X-Original-To: header which contains a copy  of  the
       envelope as it was received.

       Qmail  and  Postfix generally write a 'Delivered-To' header upon delivering the message to
       the mail spool and use it to avoid mail loops.  Qmail virtual domains however will  prefix
       the user name with a string that normally matches the user's domain. To remove this prefix
       you can use the -Q or 'qvirtual' option.

       Sometimes, unfortunately, neither of these methods works.  That	is  the  point	when  you
       should  contact	your  ISP and ask them to provide such an envelope header, and you should
       not use multidrop in this situation.  When they all fail, fetchmail must fall back on  the
       contents  of To/Cc headers (Bcc headers are not available - see below) to try to determine
       recipient addressees -- and these are unreliable.  In  particular,  mailing-list  software
       often ships mail with only the list broadcast address in the To header.

       Note that a future version of fetchmail may remove To/Cc parsing!

       When fetchmail cannot deduce a recipient address that is local, and the intended recipient
       address was anyone other than fetchmail's invoking user, mail will get lost.  This is what
       makes the multidrop feature risky without proper envelope information.

       A  related problem is that when you blind-copy a mail message, the Bcc information is car-
       ried only as envelope address (it's removed from the headers by the sending  mail  server,
       so fetchmail can see it only if there is an X-Envelope-To header).  Thus, blind-copying to
       someone who gets mail over a fetchmail multidrop link will fail unless the the  mailserver
       host  routinely	writes	X-Envelope-To or an equivalent header into messages in your mail-
       drop.

       In conclusion, mailing lists and Bcc'd mail can only work if the  server  you're  fetching
       from(1)    stores one copy of the message per recipient in your domain and(2)    records  the envelope information in a special header (X-Original-To, Delivered-To,
	      X-Envelope-To).

   Good Ways To Use Multidrop Mailboxes
       Multiple local names can be used to administer a mailing list from the client  side  of	a
       fetchmail  collection.	Suppose your name is 'esr', and you want to both pick up your own
       mail and maintain a mailing list called (say) "fetchmail-friends", and you  want  to  keep
       the alias list on your client machine.

       On  your  server,  you can alias 'fetchmail-friends' to 'esr'; then, in your .fetchmailrc,
       declare 'to esr fetchmail-friends here'.  Then, when mail including 'fetchmail-friends' as
       a  local  address  gets	fetched, the list name will be appended to the list of recipients
       your SMTP listener sees.  Therefore it will undergo alias expansion locally.  Be  sure  to
       include	'esr' in the local alias expansion of fetchmail-friends, or you'll never see mail
       sent only to the list.  Also be sure that your listener has the "me-too" option set (send-
       mail's  -oXm command-line option or OXm declaration) so your name isn't removed from alias
       expansions in messages you send.

       This trick is not without its problems, however.  You'll begin to see this when a  message
       comes  in  that	is  addressed  only to a mailing list you do not have declared as a local
       name.  Each such message will feature an 'X-Fetchmail-Warning' header which  is	generated
       because	fetchmail  cannot  find a valid local name in the recipient addresses.	Such mes-
       sages default (as was described above) to being sent to the local user running  fetchmail,
       but the program has no way to know that that's actually the right thing.

   Bad Ways To Abuse Multidrop Mailboxes
       Multidrop  mailboxes  and fetchmail serving multiple users in daemon mode do not mix.  The
       problem, again, is mail from mailing lists, which typically does not  have  an  individual
       recipient address on it.   Unless fetchmail can deduce an envelope address, such mail will
       only go to the account running fetchmail (probably root).  Also,  blind-copied  users  are
       very likely never to see their mail at all.

       If  you're tempted to use fetchmail to retrieve mail for multiple users from a single mail
       drop via POP or IMAP, think again (and reread the section on header and envelope addresses
       above).	 It  would  be smarter to just let the mail sit in the mailserver's queue and use
       fetchmail's ETRN or ODMR modes to trigger SMTP sends periodically (of course,  this  means
       you  have  to  poll  more  frequently  than the mailserver's expiry period).  If you can't
       arrange this, try setting up a UUCP feed.

       If you absolutely must use multidrop for this purpose, make sure your mailserver writes an
       envelope-address  header that fetchmail can see.  Otherwise you will lose mail and it will
       come back to haunt you.

   Speeding Up Multidrop Checking
       Normally, when multiple users are  declared  fetchmail  extracts  recipient  addresses  as
       described  above  and  checks  each  host  part	with  DNS  to see if it's an alias of the
       mailserver.  If so, the name mappings described in the "to ... here" declaration are  done
       and the mail locally delivered.

       This is a convenient but also slow method.  To speed it up, pre-declare mailserver aliases
       with 'aka'; these are checked before DNS lookups are done.  If  you're  certain	your  aka
       list  contains  all  DNS aliases of the mailserver (and all MX names pointing at it - note
       this may change in a future version) you can declare 'no  dns'  to  suppress  DNS  lookups
       entirely and only match against the aka list.

SOCKS
       Support	for  socks4/5 is a compile time configuration option. Once compiled in, fetchmail
       will always use the socks libraries and configuration on your system, there  are  no  run-
       time  switches  in  fetchmail  -  but you can still configure SOCKS: you can specify which
       SOCKS configuration file is used in the SOCKS_CONF environment variable.

       For instance, if you wanted to bypass the SOCKS proxy altogether and have  fetchmail  con-
       nect  directly,	you  could just pass SOCKS_CONF=/dev/null in the environment, for example
       (add your usual command line options - if any - to the end of this line):

       env SOCKS_CONF=/dev/null fetchmail

EXIT CODES
       To facilitate the use of fetchmail in shell scripts, an exit status code  is  returned  to
       give an indication of what occurred during a given connection.

       The exit codes returned by fetchmail are as follows:

       0      One  or  more  messages  were  successfully  retrieved  (or,  if	the -c option was
	      selected, were found waiting but not retrieved).

       1      There was no mail awaiting retrieval.  (There may have been old mail still  on  the
	      server but not selected for retrieval.) If you do not want "no mail" to be an error
	      condition (for instance, for cron jobs), use a POSIX-compliant shell and add

	      || [ $? -eq 1 ]

	      to the end of the fetchmail command line, note that this leaves 0 untouched, maps 1
	      to 0, and maps all other codes to 1. See also item #C8 in the FAQ.

       2      An error was encountered when attempting to open a socket to retrieve mail.  If you
	      don't know what a socket is, don't worry about it -- just treat this as  an  'unre-
	      coverable error'.  This error can also be because a protocol fetchmail wants to use
	      is not listed in /etc/services.

       3      The user authentication step failed.  This usually means that a bad user-id,  pass-
	      word,  or  APOP  id  was specified.  Or it may mean that you tried to run fetchmail
	      under circumstances where it did not have standard input attached to a terminal and
	      could not prompt for a missing password.

       4      Some sort of fatal protocol error was detected.

       5      There  was  a syntax error in the arguments to fetchmail, or a pre- or post-connect
	      command failed.

       6      The run control file had bad permissions.

       7      There was an error condition reported by the server.  Can also  fire  if	fetchmail
	      timed out while waiting for the server.

       8      Client-side  exclusion  error.   This  means fetchmail either found another copy of
	      itself already running, or failed in such a way that it isn't sure whether  another
	      copy is running.

       9      The  user authentication step failed because the server responded "lock busy".  Try
	      again after a brief pause!  This error is not implemented for  all  protocols,  nor
	      for all servers.	If not implemented for your server, "3" will be returned instead,
	      see above.  May be returned when talking to  qpopper  or	other  servers	that  can
	      respond with "lock busy" or some similar text containing the word "lock".

       10     The fetchmail run failed while trying to do an SMTP port open or transaction.

       11     Fatal  DNS  error.  Fetchmail encountered an error while performing a DNS lookup at
	      startup and could not proceed.

       12     BSMTP batch file could not be opened.

       13     Poll terminated by a fetch limit (see the --fetchlimit option).

       14     Server busy indication.

       23     Internal error.  You should see a message on standard error with details.

       24 - 26, 28, 29
	      These are internal codes and should not appear externally.

       When fetchmail queries more than one host, return status is 0 if  any  query  successfully
       retrieved mail. Otherwise the returned error status is that of the last host queried.

FILES
       ~/.fetchmailrc
	    default run control file

       ~/.fetchids
	    default location of file recording last message UIDs seen per host.

       ~/.fetchmail.pid
	    lock file to help prevent concurrent runs (non-root mode).

       ~/.netrc
	    your  FTP  run  control  file, which (if present) will be searched for passwords as a
	    last resort before prompting for one interactively.

       /var/run/fetchmail.pid
	    lock file to help prevent concurrent runs (root mode, Linux systems).

       /etc/fetchmail.pid
	    lock file to help prevent concurrent runs (root mode, systems without /var/run).

ENVIRONMENT
       FETCHMAILHOME
	      If this environment variable is set to a valid and existing directory name,  fetch-
	      mail  will  read	$FETCHMAILHOME/fetchmailrc  (the  dot  is  missing in this case),
	      $FETCHMAILHOME/.fetchids and $FETCHMAILHOME/.fetchmail.pid  rather  than	from  the
	      user's  home  directory.	 The .netrc file is always looked for in the the invoking
	      user's home directory regardless of FETCHMAILHOME's setting.

       FETCHMAILUSER
	      If this environment variable is set, it is used as the name  of  the  calling  user
	      (default	local name) for purposes such as mailing error notifications.  Otherwise,
	      if either the LOGNAME or USER variable is correctly set (e.g. the corresponding UID
	      matches  the  session  user  ID)	then that name is used as the default local name.
	      Otherwise getpwuid(3) must be able to retrieve a password entry for the session  ID
	      (this  elaborate	logic is designed to handle the case of multiple names per userid
	      gracefully).

       FETCHMAIL_DISABLE_CBC_IV_COUNTERMEASURE
	      (since v6.3.22): If this environment variable is set and not empty, fetchmail  will
	      disable	a   countermeasure   against   an   SSL   CBC	IV   attack  (by  setting
	      SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS).  This is a security risk, but may be necessary
	      for  connecting  to certain non-standards-conforming servers.  See fetchmail's NEWS
	      file and fetchmail-SA-2012-01.txt for details.  Earlier fetchmail versions (v6.3.21
	      and  older) used to disable this countermeasure, but v6.3.22 no longer does that as
	      a safety precaution.

       FETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS
	      (since v6.3.17): If this environment variable is set and not empty, fetchmail  will
	      always load the default X.509 trusted certificate locations for SSL/TLS CA certifi-
	      cates, even if --sslcertfile and --sslcertpath are  given.   The	latter	locations
	      take  precedence	over  the system default locations.  This is useful in case there
	      are broken certificates in the system directories and the user has no administrator
	      privileges to remedy the problem.

       HOME_ETC
	      If the HOME_ETC variable is set, fetchmail will read $HOME_ETC/.fetchmailrc instead
	      of ~/.fetchmailrc.

	      If HOME_ETC and FETCHMAILHOME are both set, HOME_ETC will be ignored.

       SOCKS_CONF
	      (only if SOCKS support is compiled in) this variable is used by the  socks  library
	      to  find	out  which  configuration  file  it should read. Set this to /dev/null to
	      bypass the SOCKS proxy.

SIGNALS
       If a fetchmail daemon is running as root, SIGUSR1 wakes it up from  its	sleep  phase  and
       forces  a  poll	of all non-skipped servers. For compatibility reasons, SIGHUP can also be
       used in 6.3.X but may not be available in future fetchmail versions.

       If fetchmail is running in daemon mode as non-root, use SIGUSR1 to wake	it  (this  is  so
       SIGHUP due to logout can retain the default action of killing it).

       Running	fetchmail in foreground while a background fetchmail is running will do whichever
       of these is appropriate to wake it up.

BUGS, LIMITATIONS, AND KNOWN PROBLEMS
       Please check the NEWS file that shipped with fetchmail for  more  known	bugs  than  those
       listed here.

       Fetchmail cannot handle user names that contain blanks after a "@" character, for instance
       "demonstr@ti on". These are rather uncommon and only hurt when using UID-based --keep set-
       ups, so the 6.3.X versions of fetchmail won't be fixed.

       Fetchmail  cannot handle configurations where you have multiple accounts that use the same
       server name and the same login. Any user@server combination must be unique.

       The assumptions that the DNS and in particular the checkalias options make are  not  often
       sustainable.  For  instance,  it has become uncommon for an MX server to be a POP3 or IMAP
       server at the same time. Therefore the MX lookups may go away in a future release.

       The mda and plugin options interact badly.  In order to collect error status from the MDA,
       fetchmail has to change its normal signal handling so that dead plugin processes don't get
       reaped until the end of the poll cycle.	This can cause resource starvation  if	too  many
       zombies	accumulate.  So either don't deliver to a MDA using plugins or risk being overrun
       by an army of undead.

       The --interface option does not support IPv6 and it is doubtful if  it  ever  will,  since
       there is no portable way to query interface IPv6 addresses.

       The RFC822 address parser used in multidrop mode chokes on some @-addresses that are tech-
       nically legal but bizarre.  Strange uses of quoting and embedded comments  are  likely  to
       confuse it.

       In  a  message with multiple envelope headers, only the last one processed will be visible
       to fetchmail.

       Use of some of these protocols requires that the program send unencrypted  passwords  over
       the  TCP/IP  connection	to  the mailserver.  This creates a risk that name/password pairs
       might be snaffled with a packet sniffer or more sophisticated monitoring software.   Under
       Linux  and FreeBSD, the --interface option can be used to restrict polling to availability
       of a specific interface device with a specific local or remote IP address, but snooping is
       still  possible	if (a) either host has a network device that can be opened in promiscuous
       mode, or (b) the intervening network link can be tapped.  We recommend the use  of  ssh(1)
       tunnelling to not only shroud your passwords but encrypt the entire conversation.

       Use of the %F or %T escapes in an mda option could open a security hole, because they pass
       text manipulable by an attacker to  a  shell  command.	Potential  shell  characters  are
       replaced  by '_' before execution.  The hole is further reduced by the fact that fetchmail
       temporarily discards any suid privileges it may have while running the MDA.   For  maximum
       safety,	however,  don't use an mda command containing %F or %T when fetchmail is run from
       the root account itself.

       Fetchmail's method of sending bounces due to errors  or	spam-blocking  and  spam  bounces
       requires that port 25 of localhost be available for sending mail via SMTP.

       If  you modify ~/.fetchmailrc while a background instance is running and break the syntax,
       the background instance will die silently.  Unfortunately, it can't die noisily because we
       don't  yet know whether syslog should be enabled.  On some systems, fetchmail dies quietly
       even if there is no syntax error; this seems to have something to do with  buggy  terminal
       ioctl code in the kernel.

       The  -f	-  option  (reading  a	configuration from stdin) is incompatible with the plugin
       option.

       The 'principal' option only handles Kerberos IV, not V.

       Interactively entered passwords are truncated after 63 characters. If you really  need  to
       use a longer password, you will have to use a configuration file.

       A  backslash  as  the  last  character of a configuration file will be flagged as a syntax
       error rather than ignored.

       The BSMTP error handling is virtually nonexistent and may leave broken messages behind.

       Send  comments,	bug  reports,  gripes,	and  the  like	to   the   fetchmail-devel   list
       <fetchmail-devel@lists.berlios.de>

       An HTML FAQ <http://fetchmail.berlios.de/fetchmail-FAQ.html> is available at the fetchmail
       home page, it should also accompany your installation.

AUTHOR
       Fetchmail is currently maintained by Matthias Andree and Rob Funk  with	major  assistance
       from Sunil Shetye (for code) and Rob MacGregor (for the mailing lists).

       Most  of the code is from Eric S. Raymond <esr@snark.thyrsus.com> .  Too many other people
       to name here have contributed code and patches.

       This program is descended from and replaces popclient, by Carl Harris <ceharris@mal.com> ;
       the  internals  have  become quite different, but some of its interface design is directly
       traceable to that ancestral program.

       This manual page has been improved by  Matthias	Andree,  R. Hannes  Beinert,  and  Hector
       Garcia.

SEE ALSO
       README, README.SSL, README.SSL-SERVER, The Fetchmail FAQ <http://www.fetchmail.info/
       fetchmail-FAQ.html>, mutt(1), elm(1), mail(1), sendmail(8), popd(8), imapd(8), netrc(5).

       The fetchmail home page.  <http://fetchmail.berlios.de/>

       The maildrop home page.	<http://www.courier-mta.org/maildrop/>

APPLICABLE STANDARDS
       Note that this list is just a collection of references and  not	a  statement  as  to  the
       actual protocol conformance or requirements in fetchmail.

       SMTP/ESMTP:
	    RFC 821, RFC 2821, RFC 1869, RFC 1652, RFC 1870, RFC 1983, RFC 1985, RFC 2554.

       mail:
	    RFC 822, RFC 2822, RFC 1123, RFC 1892, RFC 1894.

       POP2:
	    RFC 937

       POP3:
	    RFC  1081,	RFC 1225, RFC 1460, RFC 1725, RFC 1734, RFC 1939, RFC 1957, RFC 2195, RFC
	    2449.

       APOP:
	    RFC 1939.

       RPOP:
	    RFC 1081, RFC 1225.

       IMAP2/IMAP2BIS:
	    RFC 1176, RFC 1732.

       IMAP4/IMAP4rev1:
	    RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061, RFC 2195, RFC 2177, RFC 2683.

       ETRN:
	    RFC 1985.

       ODMR/ATRN:
	    RFC 2645.

       OTP: RFC 1938.

       LMTP:
	    RFC 2033.

       GSSAPI:
	    RFC 1508, RFC 1734, Generic Security Service Application Program Interface (GSS-
	    API)/Kerberos/Simple Authentication and Security Layer (SASL) Service Names <http://
	    www.iana.org/assignments/gssapi-service-names/>.

       TLS: RFC 2595.

fetchmail				 fetchmail 6.3.24			     fetchmail(1)
Unix & Linux Commands & Man Pages : ©2000 - 2018 Unix and Linux Forums


All times are GMT -4. The time now is 03:03 PM.

Unix & Linux Forums Content Copyright©1993-2018. All Rights Reserved.
×
UNIX.COM Login
Username:
Password:  
Show Password





Not a Forum Member?
Forgot Password?