1. PDA synchronization software with your PDA in the cradle.
2. WinFax Pro (especially 10.02 in Outlook 2003) - contact their support
for an alleged fix.
3. Franklin-Cover Plan Plus!
4. COM Add-ins.
5. Mail reminder add-ins that keep a stub of Outlook open in the background
to check for new mail and fire reminders.
6. Anti-virus/firewall programs that are set to scan incoming and outgoing
mail.