Outlook Freezes when sending email

[Steve]

PLEASE HELP!!!!!

When I attempt to send an email in Outlook 2000 (Office
2000 Professional), it freezes, and I get an error report,
asking me if I want to send or Don't send to Microsoft.

I am using Windows XP Professional. My mailbox was very
large in size, but when I delted emails, the problem went
away for a day. However, it has now returned.

Any ideas? Virus??? I did a full scan with updated virus
definitions, and it did not reveal anything.

Thanks,
Steve