qmail-command - user-specified mail delivery program
in .qmailext: |command
qmail-alias will, upon your request, feed each incoming
mail message through a program of your choice.
When a mail message arrives, qmail-alias runs sh -c com-
mand in your home directory. It makes the message avail-
able on command's standard input.
WARNING: The mail message does not begin with qmail-
alias's usual Return-Path and Delivered-To lines.
Note that qmail-alias uses the same file descriptor for
every delivery in your .qmail file, so it is not safe for
command to fork a child that reads the message in the
background while the parent exits.
command's exit codes are interpreted as follows: 0 means
that the delivery was successful; 99 means that the deliv-
ery was successful, but that qmail-alias should ignore all
further delivery instructions; 71, 74, 75, 111, or 120
means that the delivery failed but should be tried again
in a little while; anything else means that the delivery
qmail-alias supplies several useful environment variables
to command. SENDER is the envelope sender address.
NEWSENDER is the forwarding envelope sender address, as
described in dot-qmail(5). RECIPIENT is the envelope
recipient address, local@domain. USER is user. HOME is
your home directory, homedir. HOST is the domain part of
the recipient address. LOCAL is the local part. EXT is
the .qmail extension, ext. EXT2 is the portion of EXT
following the first dash; EXT3 is the portion following
the second dash; EXT4 is the portion following the third
dash. DTLINE and RPLINE are the usual Delivered-To and
Return-Path lines, including newlines. UFLINE is the
UUCP-style From_ line that qmail-alias adds to mbox-format
WARNING: These environment variables are not quoted. They
may contain special characters. They are under the con-
trol of a possibly malicious remote user.
dot-qmail(5), envelopes(5), qmail-alias(8)