[Mailman-Developers] envelope header checking

[Nadim Shaikli]

I have a number of lists that I administer that seem to have come across
a nasty quirk.  I use postfix and spamassassin to keep spam in check but
recently I've noticed something different.

I disallow any posts coming in externally with @my_domain via postfix
(it uses the envelope sender to do the checks).  Mailman, on the other
hand, uses the header From: field and thus the problem.

I've recently got mails that looks like this,

 From him at outside.com
 Date: blah blah
 From: me at my_domain.com

so postfix processes it and allows it into my queues (after all it is not
being spoofed - the envelope (first From) is clean).  Mailman though sizes
up this email based on the From: header field and denotes it a locally
generate post which I allow irrespective of subscription (I have non-member
filtering to allow posts from '.*@my_domain.com' through via the
'accept_these_nonmembers' setting).

So I have 2 questions,

 1. Anyone know of a decent way to make sure that both the envelope sender
    and the noted From header field do in fact match ? else reject/discard
    the email.

 2. Does mailman allow one to check the envelope sender instead of the
    From: header field ?  That way I know both postfix and mailman are
    looking at the same thing.

I'm using postfix-2.0.16; question-1 above also needs to account for myself
being able to mail out without issue (ie. in case someone suggests header
filtering within postfix -- that would stop internal emails from going out
and I'm unable to upgrade to postfix-2.1 just yet which seems to have hooks
for this now).

Regards,

 - Nadim



	
		
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