After recently migrating from Exchange 2003 to Exchange 2010, users have begun to receive random emails that have blank message bodies but the subjects and other data is intact. (We are currently in coexistence but all mailboxes are on 2010 and mail routes correctly, etc)
OWA displays these messages without issue. Outlook clients range from 2003-2007, I am still trying to see if it occurs only in 2003. Encrypted communications on Exchange has been disabled for the 2003 clients to work (plan to re-enable it client and server side at a later date).
There is no AV filtering on the clients for email, and the blank email is received locally within the organization as well as from outbound sources.
Is it possible a certificate problem could cause this? Again, OWA seems to display the messages fine.