outbox item stalled other messages can't send;can't delete item

[NW1000]

A single mail item has been stuck in my outbox for three days. Other
outbound messages are getting stuck behind it. I can receive messages, and
occasionally one of my outbound messages makes it out, but the stuck message
is slowing things down tremendously. I cannot delete it. When I try to open
it, it get the message "Outlook has already begun transmitting." If anyone
knows how to remove a message from behind the scenes, I'd appreciate the help.
Thank you.

 

[Diane Poremsky {MVP}]

set outlook offline (see file menu) and wait 5 min before deleting.
http://www.outlook-tips.net/howto/stuck_message.htm

 

[K. Orland]

You can go into your Outbox, open the offending email, close it, then delete
it. Other methods are described here:

http://www.howto-outlook.com/faq/messagestuckinoutbox.htm