aliases(4)							   File Formats 							aliases(4)

NAME

       aliases, addresses, forward - addresses and aliases for sendmail

SYNOPSIS

       /etc/mail/aliases

       /etc/mail/aliases.db

       /etc/mail/aliases.dir

       /etc/mail/aliases.pag

       ~/.forward

DESCRIPTION

       These files contain mail addresses or aliases, recognized by sendmail(1M) for the local host:

       /etc/passwd

	   Mail addresses (usernames) of local users.

       /etc/mail/aliases

	   Aliases for the local host, in ASCII format. Root can edit this file to add, update, or delete local mail aliases.

       /etc/mail/aliases.{dir , pag}

	   The	aliasing  information  from /etc/mail/aliases, in binary ndbm(3C) format for use by sendmail(1M). The program newaliases(1M) main-
	   tains these files.

       /etc/mail/aliases.db

	    The aliasing information from /etc/mail/aliases, in binary, Berkeley DataBase format for use by sendmail(1M).  The	program  maintains
	   these files.

	   Depending on the configuration of the AliasFile option in /etc/mail/sendmail.cf, either the single file aliases.db or the pair of files
	   aliases.{dir, pag} is generated by newaliases(1M). As shipped with Solaris, sendmail(1M) supports both formats. If  neither	is  speci-
	   fied, the Berkeley DataBase format which generates the single .db file is used.

       ~/.forward

	   Addresses to which a user's mail is forwarded (see Automatic Forwarding).

       In  addition, the NIS name services aliases map mail.aliases, and the NIS+ mail_aliases table, both contain addresses and aliases available
       for use across the network.

   Addresses
       As distributed, sendmail(1M) supports the following types of addresses:

   Local Usernames
	 username

       Each local username is listed in the local host's /etc/passwd file.

   Local Filenames
	 pathname

       Messages addressed to the absolute pathname of a file are appended to that file.

   Commands
	 |command

       If the first character of the address is a vertical bar (|), sendmail(1M) pipes the message to the standard input of the  command  the  bar
       precedes.

   Internet-standard Addresses
	 username@domain

       If  domain  does  not contain any `.' (dots), then it is interpreted as the name of a host in the current domain. Otherwise, the message is
       passed to a mailhost that determines how to get to the specified domain. Domains are divided into subdomains separated by  dots,  with  the
       top-level domain on the right.

       For example, the full address of John Smith could be:

	 js@jsmachine.Podunk-U.EDU

       if he uses the machine named jsmachine at Podunk University.

   uucp Addresses
	 ... [host!] host!username

       These  are sometimes mistakenly referred to as ``Usenet'' addresses. uucp(1C) provides links to numerous sites throughout the world for the
       remote copying of files.

       Other site-specific forms of addressing can be added by customizing the sendmail.cf configuration file. See sendmail(1M) for details. Stan-
       dard addresses are recommended.

   Aliases
   Local Aliases
       /etc/mail/aliases is formatted as a series of lines of the form

	 aliasname:address[, address]

       aliasname  is the name of the alias or alias group, and address is the address of a recipient in the group. Aliases can be nested. That is,
       an address can be the name of another alias group. Because of the way sendmail(1M) performs  mapping  from  upper-case  to  lower-case,	an
       address that is the name of another alias group must not contain any upper-case letters.

       Lines beginning with white space are treated as continuation lines for the preceding alias. Lines beginning with # are comments.

   Special Aliases
       An alias of the form:

	 owner-aliasname : address

       sendmail  directs  error-messages resulting from mail to aliasname to address, instead of back to the person who sent the message. sendmail
       rewrites the SMTP envelope sender to match this, so owner-aliasname should always point to alias-request, and alias-request should point to
       the owner's actual address:

	 owner-aliasname:      aliasname-request
	 aliasname-request     address

       An alias of the form:

	 aliasname: :include:pathname

       with  colons  as shown, adds the recipients listed in the file pathname to the aliasname alias. This allows a private list to be maintained
       separately from the aliases file.

   NIS and NIS+ Domain Aliases
       The aliases file on the master NIS server is used for the mail.aliases NIS map, which can be  made  available  to  every  NIS  client.  The
       mail_aliases  table serves the same purpose on a NIS+ server. Thus, the /etc/mail/aliases* files on the various hosts in a network will one
       day be obsolete. Domain-wide aliases should ultimately be resolved into usernames on specific hosts. For example, if the following were	in
       the domain-wide alias file:

	 jsmith:js@jsmachine

       then any NIS or NIS+ client could just mail to jsmith and not have to remember the machine and username for John Smith.

       If  a  NIS or NIS+ alias does not resolve to an address with a specific host, then the name of the NIS or NIS+ domain is used. There should
       be an alias of the domain name for a host in this case.

       For example, the alias:

	 jsmith:root

       sends mail on a NIS or NIS+ client to root@podunk-u if the name of the NIS or NIS+ domain is podunk-u.

   Automatic Forwarding
       When an alias (or address) is resolved to the name of a user on the local host, sendmail(1M) checks for a ~/.forward  file,  owned  by  the
       intended  recipient,  in that user's home directory, and with universal read access. This file can contain one or more addresses or aliases
       as described above, each of which is sent a copy of the user's mail.

       Care must be taken to avoid creating addressing loops in the ~/.forward file. When forwarding mail between machines, be sure that the  des-
       tination  machine  does	not  return  the mail to the sender through the operation of any NIS aliases. Otherwise, copies of the message may
       "bounce." Usually, the solution is to change the NIS alias to direct mail to the proper destination.

       A backslash before a username inhibits further aliasing. For instance, to invoke the vacation program, user js creates  a  ~/.forward  file
       that contains the line:

	 js, "|/usr/ucb/vacation js"

       so that one copy of the message is sent to the user, and another is piped into the vacation program.

       The  ~/.forward	file can be used to specify special "per user" extensions by creating a .forward+extension file in the home directory. For
       example, with an address like jsmith+jerry@jsmachine, the sendmail(1M) utility recognizes everything before the "+" as the actual  username
       (jsmith) and everything after it, up to the "@" symbol, as the extension (jerry) which is passed to the mail delivery agent for local use.

       The default value of the ForwardPath processing option in sendmail(1M) is:

	 O ForwardPath=$z/.forward.$w+$h:$z/.forward+$h:$z/.forward.$w:$z 
	 /.forward

       where  $z is the macro for the user's home directory, $w is the macro for the local machine name and $h is the extension.  For example, for
       mail using the address, jsmith+jerry@jsmachine, the sendmail(1M) utility checks each of the four following file names, in the order  given,
       to see if it exists and if it has "safe" permissions, that is, that neither the file nor any of its parent directories are group- or world-
       writable:

	 ~jsmith/.forward.jsmachine+jerry
	 ~jsmith/.forward+jerry
	 ~jsmith/.forward.jsmachine
	 ~jsmith/.forward

       The first file that meets the conditions is used to forward the mail, that is, all the entries in that file receive a copy of the mail. The
       search is then stopped.

FILES

       /etc/passwd		Password file

       /etc/nsswitch.conf	Name service switch configuration file

       /etc/mail/aliases	Mail aliases file (ascii)

       /etc/mail/aliases.db	Database of mail aliases (binary)

       /etc/mail/aliases.dir	Database of mail aliases (binary)

       /etc/mail/aliases.pag	Database of mail aliases (binary)

       /etc/mail/sendmail.cf	sendmail configuration file

       ~/.forward		Forwarding information file

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWsndmr 		   |
       +-----------------------------+-----------------------------+

SEE ALSO

       passwd(1), uucp(1C), vacation(1), newaliases(1M), sendmail(1M), ndbm(3C), getusershell(3C), passwd(4), shells(4), attributes(5)

NOTES

       Because	of  restrictions in ndbm(3C), a single alias cannot contain more than about 1000 characters (if this format is used). The Berkeley
       DataBase format does not have any such restriction. Nested aliases can be used to circumvent this limit.

       For aliases which result in piping to a program or concatenating a file, the shell of the controlling user must be  allowed.  Which  shells
       are and are not allowed are determined by getusershell(3C).

SunOS 5.11							    8 May 2006								aliases(4)