In response to a question on mailman-users, I looked at AvoidDups.py, and I see that if an address is in the Cc: header of a post and is a candidate recipient and is a list member with DontReceiveDupes set, the address is removed from the recipient list and from the Cc: header of the post.
I understand why it is removed from the recipient list - that's the whole point - but does anyone know/remember why it is also removed from the Cc: header? This seems unnecessary and inconsistent since it isn't removed from To:, Resent-To: or Resent-Cc:.
Also, there is a docstring in the module that refers to an in memory Message-Id: list for avoiding cross-posted dups which I think was in the original patch, but was never incorporated. Perhaps this should be rewritten.
-- Mark Sapiro <msapiro@value.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan