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 temporary 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 examples,

          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)