Ubuntu Manpage: qmail-smtpd - receive mail via SMTP

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.