[Mailman-Developers] message posting in a loop with mailman 2.1b1

[Marc MERLIN]

I just upgraded one of my servers to exim 4 and mailman choked badly on having 
exim refuse a message because exim did this:

DNS lookup of scruznet.com (MX) gave TRY_AGAIN
scruznet.com in dns_again_means_nonexist? no (option unset)
returning DNS_AGAIN
lookuphost router: defer for champney@scruznet.com
  message: host lookup did not complete
----------- end verify ------------
accept: condition test deferred
SMTP>> 451 Temporary local problem - please try later

The problem is that mailman decided  that the whole post failed, and started
to resend it in a loop.
Apr 15 08:13:56 2002 (17389) post to keskydee from jean-luc@maisiere.com, size=3527, 9 failures
Apr 15 08:17:54 2002 (17389) post to keskydee from jean-luc@maisiere.com, size=3527, 7 failures
Apr 15 08:22:08 2002 (17389) post to keskydee from jean-luc@maisiere.com, size=3527, 8 failures
(...)


This  also caused  bounce  scores  against all  the  users  and angered  the
membership obviously.
I'm not  sure how mailman  could deal better with  that, granted, it  can be
fixed on the exim side, but the  problem is not obvious and the looping post
is nasty.
Since mailman doesn't know who many receipients it delivered to when it gets
an error  from the  MTA (4xx  or 5xx),  I recommend  that mailman  moves the
message in a  separate queue dir, logs an error  (possibly Emailing the list
owner in  the process)  and gives  up on the  message. 
Resending  it is  only going  to piss  off the  users that  are getting  the
message each time mm tries.

BTW, on the exim 4 side, I had:
  accept  hosts         = +localadds:+relay_from_hosts
          verify        = recipient

I solved the problem by adding this at the beginning of my rcpt ACL:
  accept  hosts         = 127.0.0.1

Marc
-- 
Microsoft is to operating systems & security ....
                                      .... what McDonalds is to gourmet cooking
  
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