I was going through the bounce log and came across a few lines which made me scratch my head:
Jul 30 19:09:55 2003 (16079) bounce message with non-members of mail-news: email@example.com
Jul 30 19:24:15 2003 (16079) bounce message with non-members of mail-news: ".slob85"@hotmail.com
checking the addresses indiviually I found that they were part of our lists. So I did some research (asked the local guru) who passed me following snippet.
if not foundp: # It means an address was recognized but it wasn't an address # that's on any mailing list at this site. BAW: don't forward # these, but do log it. syslog('bounce', 'bounce message with non-members of %s: %s', listname, COMMASPACE.join(addrs))
Quite clearly to me the addresses in question need to be stripped() and unquoted when compared with existing addresses; it seems quoting is necessary for all addresses which begin or end in "." This might improve Mailman's bounce recognition considerably. There were other things I came across which might also be possible but would require considerably more complex to implement.
I'm not very good with CVS or code in general so I would have to submit a function or module patch en bloc to someone who knows what to do with it.