The following question comes up often: "The 'Sending' message dialog comes up although nothing is in the Outbox. It's now progressed sequentially from 'Sending' 1 message to 'Sending 1 of 4'. It takes ages for 'real' messages to be sent."
It's a bug. Outlook has a problem counting. It counts each account it checks for new mail as a message. In the case of "1 of 4", it means there are 4 accounts in the profile it’s checking.
Until a fix is released, try putting the accounts in different send /receive groups so each is checked at a different time. (Press Ctrl+Alt+S to open the Send/Receive dialog).
Published June 19, 2008. Last updated on May 23, 2011.