Some of our users are getting emails with attachments that are appearing as the mime data still encoded.
Usually 1 in 40 emails with an attachment will just have the raw data (plain text and html syntax and mime encoded attachments) plus there will be strange =20 strings added.
The users are Outlook 2007 with Exchange 2003 performing pop3 pulls every 15mins.
There is AVG network edition with the pop3 scanner running.
If the user asks the sender to resend the message comes through just fine and its not happening from a specific domain, it appears to be a server issue.