[J C Lawrence]

5. MH-style archive folders, split out by archive period, instead of mbox'es (message separation semantics with mbox are not guaranteed).

While MH-style archive folders could be a nice feature, I don't think your comment on the message separation semantics of mbox folders is entirely correct.

Sendmail (and compatible MTAs) actually _quote_ any lines beginning with "From " in the message body when delivering locally to avoid breaking the message separators.

[ I've heard rumours that Postfix doesn't put any "From " quasi-header in pipe-delivered messages at all (while it does add "Delivered-To:" headers containing the envelope recipient (and use these headers to kill forwarding loops -- this may actually be a clue to the problems people have getting Mailman and Postfix working together)).

If this indeed is the case, then there would (from Postfix' point of view) be no need to quote any "From " lines in the body of the message, either -- and this could break the message separation semantics of Mailman's mbox-style folders. Whether the proper fix is for Mailman to quote any "From " lines on it's own, or switch to using some other folder format, is at this time unclear to me. ]

Harald