qmail-smtpd(8)                                                System Manager's Manual                                               qmail-smtpd(8)

NAME

       qmail-smtpd - receive mail via SMTP

SYNOPSIS

       qmail-smtpd

DESCRIPTION

       qmail-smtpd  receives  mail messages via the Simple Mail Transfer Protocol (SMTP) and invokes qmail-queue to deposit them into the outgoing
       queue.  qmail-smtpd must be supplied several environment variables; see tcp-environ(5).

       qmail-smtpd is responsible for counting hops.  It rejects any message with 100 or more Received or Delivered-To header fields.

       qmail-smtpd supports ESMTP, including the 8BITMIME and PIPELINING options.

TRANSPARENCY

       qmail-smtpd converts the SMTP newline convention into the UNIX newline convention by converting CR LF into  LF.   It  returns  a  temporary
       error and drops the connection on bare LFs; see http://pobox.com/~djb/docs/smtplf.html.

       qmail-smtpd accepts messages that contain long lines or non-ASCII characters, even though such messages violate the SMTP protocol.

CONTROL FILES

       badmailfrom
            Unacceptable  envelope sender addresses.  qmail-smtpd will reject every recipient address for a message if the envelope sender address
            is listed in badmailfrom.  A line in badmailfrom may be of the form @host, meaning every address at host.

       databytes
            Maximum number of bytes allowed in a message, or 0 for no limit.  Default: 0.  If a message exceeds this limit, qmail-smtpd returns  a
            permanent  error code to the client; in contrast, if the disk is full or qmail-smtpd hits a resource limit, qmail-smtpd returns a tem-
            porary error code.

            databytes counts bytes as stored on disk, not as transmitted through the network.  It does not count the  qmail-smtpd  Received  line,
            the qmail-queue Received line, or the envelope.

            If the environment variable DATABYTES is set, it overrides databytes.

       localiphost
            Replacement  host  name for local IP addresses.  Default: me, if that is supplied.  qmail-smtpd is responsible for recognizing dotted-
            decimal addresses for the current host.  When it sees a recipient address of the form box@[d.d.d.d],  where  d.d.d.d  is  a  local  IP
            address, it replaces [d.d.d.d] with localiphost.  This is done before rcpthosts.

       morercpthosts
            Extra allowed RCPT domains.  If rcpthosts and morercpthosts both exist, morercpthosts is effectively appended to rcpthosts.

            You must run qmail-newmrh whenever morercpthosts changes.

            Rule of thumb for large sites: Put your 50 most commonly used domains into rcpthosts, and the rest into morercpthosts.

       rcpthosts
            Allowed  RCPT  domains.   If rcpthosts is supplied, qmail-smtpd will reject any envelope recipient address with a domain not listed in
            rcpthosts.

            Exception: If the environment variable RELAYCLIENT is set, qmail-smtpd will ignore rcpthosts, and will append the value of RELAYCLIENT
            to each incoming recipient address.

            rcpthosts may include wildcards:

               heaven.af.mil
               .heaven.af.mil

            Envelope recipient addresses without @ signs are always allowed through.

       smtpgreeting
            SMTP  greeting  message.   Default: me, if that is supplied; otherwise qmail-smtpd will refuse to run.  The first word of smtpgreeting
            should be the current host's name.

       timeoutsmtpd
            Number of seconds qmail-smtpd will wait for each new buffer of data from the remote SMTP client.  Default: 1200.

RECIPIENT VERIFICATION

       Recipient verification is enabled with the VERIFY environment variable. This can be used to  specify  per-recipient  rejection  of  invalid
       recipient addresses (immediate verification causing a permanent 550 error response to the RCPT command), or deferred rejection at DATA time
       (554 response) of the whole session if any recipient addresses don't exist.

       To verify an address, qmail-smtpd uses a separate qmail-verify UDP server. By default this will be on the loopback address 127.0.0.1,  port
       11113. Enable verification like this,

          VERIFY=":"

          VERIFY="DEFER"

       (for immediate, deferred verification respectively). A different IP address and/or port can be specified for qmail-verify as in these exam-
       ples,

          VERIFY="192.168.1.1"
          VERIFY=":10101"
          VERIFY="DEFER,:10101"
          VERIFY="DEFER,192.168.1.1:10101"

       Recipient verification may be explicitly disabled by setting VERIFY to an empty string,

          VERIFY=""

       Addresses with domains appearing in control/rcpthosts but not  in  control/locals  or  control/virtualdomains  will  be  considered  valid,
       reflecting qmail's standard behaviour.

       Note that if the environment variable RELAYCLIENT is set, no checking is carried out.

       qmail-verify  needs  to  be  running  to respond to recipient verification queries. If no qmail-verify response is received a temporary 451
       error response is given to the remote system and the session terminated.

SEE ALSO

       tcp-env(1), tcp-environ(5), qmail-control(5), qmail-inject(8), qmail-newmrh(8), qmail-queue(8), qmail-remote(8), qmail-verify(8)

                                                                                                                                    qmail-smtpd(8)