One of Outlook's troubleshooting options is logging send/receive. While it's a great help when you have problems sending and receiving, it should only be enabled when you have problems as it can cause Outlook to crash, especially if you use IMAP accounts.

Look for the logging option in Tools Options, Other, Advanced. You'll find the log in your temp folder. On WindowsXP, this is at C:\Documents and Settings\username\Local Settings\Temp