Server is actually Exchange 2007 SP3
I have a DDL (one of about 150) and a couple related Hub Transport rules that cc a handful of other individuals when this particular DDL is in the To or CC fields.
If I preview the membership in either EMC or EMS I see the proper list of members.
If I email the DDL it expands to no members (according to Message Tracking Event ID EXPAND) - no errors as far as I can tell, but no members. Message Tracking shows two result: RECEIVE and EXPAND. After that it just disappears and the related Hub Transport rules are not processed.
If I email the DDL and cc myself it will still expand to no members but the Hub Transport rules kick in and those people are cc'd on the message. In other words, the people cc'd via Hub Transport rule get the message but the actual members of the DDL still do not.
Any ideas out there on what might be causing this?