If you’re running Outlook 2010 Beta (build 4536) and suffering from the message size bug, you can now fix it with a special update for the Office 2010 Beta.

The Outlook Team has released an update for both the 32-bit and the 64-bit version of Office 2010 Beta.

Download: Outlook 2010 Beta fix for 32-bit Office 2010
Download: Outlook 2010 Beta fix for 64-bit Office 2010