Rewriting email headers in exim
by Juliet Kemp
Recently the people running our centralised email server decided to increase its security. Among other things, this meant that if the From: header of an email didn't match a registered user, it would be bounced back. I have a couple of pieces of software (RT and Hobbit, notably), that run as a particular userid and send mail as that ID, so since those weren't "real" users, the mails started bouncing.
I have found two ways of dealing with this, using
- More complicated. Use
sendmail -f email@example.com the mail command within the program (this works for RT but not for Hobbit). The
-fflag rewrites the envelope-from — you will also need to put the line
update-exim4.conf, and restart exim. This allows any user to rewrite the envelope-from. This does have security implications if you mistrust your users (in this particular instance, these are servers without user access so I'm not too worried).
- Rather easier. Edit
/etc/email-addressesto include a line:
problemuid: firstname.lastname@example.orgYou don't need the
dc_untrusted_set_serverline. You probably don't even need to restart exim. (I did because I'm like that.)
I worked out the more complicated one first, obviously. Oh well.