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.

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