We have recently upgraded Outlook on a few machines from 2000 to 2002. The computers are running Windows 2000, Windows XP Pro and Windows 2000 Terminal Server. On the back-end, we're using Exchange 5.5 running on Windows 2000 Server (NT Domain) with Symantec Antivirus for MSE in MAPI/VAPI combination mode. We've found that when sending attachments, we're presented with this error message that never came up with OL 2000:
Task 'Microsoft Exchange Server - Sending' reported error (0x80004005) : 'The operation failed.'
The error appears on the "Errors" tab of the "Outlook Send/Receive Progress" dialog. Even though we get this message, the email stays in the outbox and goes out successfully moments later.
Additionally, we upgraded another instance of Office to Outlook 2003 with a similar, but not exact problem. Under 2003, the message goes out, but bounces back. The error on the bounced message complains that the message is being scanned for viruses. Under 2003, the message never goes out. It must be resent several times before it actually goes out.