My Postfix server handles message for a dozen domains, for one of these
domains, I want the subject replaced with the recipient's local part, so
something like this, but put in a format that Postfix understands:
# domain3.com is the one recipient domain we want affected by this rule
# $recipient_name the recipient localpart, so "joe" if the recipient is
# [email protected]
IF $recipient_domain = 'domain3.com'
REPLACE $subject WITH $recipient_name
ENDIF
I think I need to setup a smtp_header_checks file, but the more I look
at it the harder my head hurts.
That's not possible alas, see the section BUGS at
http://www.postfix.org/header_checks.5.html : "Many people overlook the
main limitations of header and body_checks rules. These rules operate on
one logical message header or one body line at a time. A decision made for
one line is not carried over to the next line."
IOW, the only things you can do with smtp_header_checks is to replace a
Subject: line with another Subject: line, possibly based on the contents
of the original Subject: line if you use regexp backreferences. But there
is no way to use the recipient name or domain in such rules.
For cases like the one you have in mind, it is necessary to use a milter.
Gregory
