When starting Outlook it says it is sending but outbox is empty?

Every time I open Outlook 2003, it says it's sending 1 of three messages, but I have no messages waiting to go out. Is there a cache I need to clear somewhere?
Should I be looking for something else. The attempt to send when there is nothing there is taking up alot of time.Thanks

 

empty outbox sending emails

This has happened to me also. The problem occurred because I have 2 email accounts configured in outlook. I had a message in my outbox going out on my default pop3 server. However, that pop3 server was down, so I opened up the email in my outbox and switched it to go out my other pop3 account. The email went out successfully. However, outlook continues to try to send a now missing email to the original pop3. Of course that fails because there isn't a message there.
This is truly a phantom email in outlook. There must be some sort of outlook cache that has the phantom email in it that I can clean. Does this ring a bell w/ anyone?

 

Okay, more research reveals that in my case it was a read-receipt that was stuck in my outbox which is why it was invisible. Outlook-Spy can be used to delete it.

http://www.pcreview.co.uk/forums/thread-804015.php