Name
$@
Synopsis
Beginning with V8.7, the RHS of a rule to select an
error
delivery agent can look like this:
R... $#error $@ dsn $:text of error message here
The text following the $
: is the actual error
message text that will be included in bounced mail or sent back to a
connecting SMTP host. The numbers following the $@
specify the DSN error to be returned. For example:
R$* < @ spam.host > $* $#error $@ 5.7.1 $: 550 You are a spammer, go away
Here, the number following the $@
contains a dot,
so it is interpreted as a DSN status expression. The
.7.
in the number causes
sendmail to set its exit value to EX_DATAERR.
The 5.7.1
itself is defined in RFC1893 as meaning
“Permanent failure, delivery not authorized, message
refused.” Note that if the number following the
$@
does not contain a dot,
sendmail sets its exit(2)
value to that number.
The use of $@
to specify the DNS return value for
the error
delivery agent is described in detail in
error.
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