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 https://cr.yp.to/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)