The DMARC Wrap Message action is incompatible with some older Python email libraries.

[Mark Sapiro]

There is a bug in Python's email package (See <http://bugs.python.org/issue7970>) which is fixed in recent versions, but which causes Mailman's OutgoingRunner process to throw a "TypeError: Expected list, got <type 'str'>" exception on outgoing messages wrapped by the DMARC Wrap Message action.

This bug does not exist in Python 2.6.5 and later. It does exist in all Python 2.5.x and earlier. It is not known to me in which Python 2.6.x (x <= 5) it was fixed.

It will cause any outgoing individual messages to which the DMARC Wrap Message action was applied to be shunted and not delivered.