It seems that my Mac Entourage user that sends files via exchange server results in 100% corrupted files to recipients. At first, it was happening to attachments sent to my other email account as well, but since I installed SP1 on exchange, it seemed to fix my problem. However, users on the network at the office still get the same corrupted problems as they did before. In essence, the SP1 only fixed half of the problem.
I checked to make sure AppleDouble encoding was not being used, installed all the latest updates on all machines, etc. Still no dice. Any suggestions?