Blank emails

Recently i have been receiving blank emails, no subject no recipient and no body. The blank email gets delivered and then like in 2 minutes i start getting hit by spam. My spam killer (spamfire) used to delete these spam emails but since i have been receiving the blank emails my spamfire gives me an error message saying “connection to my server has been dropped”

Then when i manually go into Outlook (2003) and delete the blank email my spamfire works properly.

Any ideas of what is going on?

Also i am running outlook and exchange 2000 server.

Any ideas will help!

Thanks,