.TH qmail-command 8
.SH NAME
qmail-command \- user-specified mail delivery program
.SH SYNOPSIS
in
.BR .qmail\fIext :
.B |\fIcommand
.SH DESCRIPTION
.B qmail-local
will, upon your request,
feed each incoming mail message through a program of your choice.

When a mail message arrives,
.B qmail-local
runs
.B sh -c \fIcommand
in your home directory.
It makes the message available on 
.IR command 's
standard input.

.B WARNING:
The mail message does not begin with
.BR qmail-local 's
usual
.B Return-Path
and
.B Delivered-To
lines.

Note that
.B qmail-local
uses the same file descriptor for every delivery
in your
.B .qmail
file, so it is not safe for
.I command
to fork a child that
reads the message in the background while the parent exits.
.SH "EXIT CODES"
.IR command 's
exit codes are interpreted as follows:
0 means that the delivery was successful;
99 means that the delivery was successful,
but that
.B qmail-local
should ignore all further delivery instructions;
100 means that the delivery failed permanently (hard error);
111 means that the delivery failed but should be tried again
in a little while (soft error).

Currently 64, 65, 70, 76, 77, 78, and 112 are considered hard errors,
and all other codes are considered soft errors,
but
.I command
should avoid relying on this.
.SH "ENVIRONMENT VARIABLES"
.B qmail-local
supplies several useful environment variables to
.IR command .
.B WARNING:
These environment variables are not quoted.
They may contain special characters.
They are under the control of a possibly malicious remote user.

.B SENDER
is the envelope sender address.
.B NEWSENDER
is the forwarding envelope sender address,
as described in
.BR dot-qmail(5) .
.B RECIPIENT
is the envelope recipient address,
.IR local@domain .
.B USER
is
.IR user .
.B HOME
is your home directory,
.IR homedir .
.B HOST
is the
.I domain
part of the recipient address.
.B LOCAL
is the
.I local
part.
.B EXT
is the
address extension,
.IR ext .

.B HOST2
is the portion of
.B HOST
preceding the last dot;
.B HOST3
is the portion of
.B HOST
preceding the second-to-last dot;
.B HOST4
is the portion of
.B HOST
preceding the third-to-last dot.

.B EXT2
is the portion of
.B EXT
following the first dash;
.B EXT3
is the portion
following the second dash;
.B EXT4
is the portion
following the third dash.
.B DEFAULT
is the portion
corresponding to the
.B default
part of the
.BR .qmail\- ...
file name;
.B DEFAULT
is not set if
the file name does not end with
.BR default .

.B DTLINE
and
.B RPLINE
are the usual
.B Delivered-To
and
.B Return-Path
lines,
including newlines.
.B UFLINE
is the UUCP-style
.B From_
line that
.B qmail-local
adds to
.IR mbox -format
files.
.SH "SEE ALSO"
dot-qmail(5),
envelopes(5),
qmail-local(8)