Outlook won't allow me to delete message

[Bruce]

I tried to forward an email message and it did not work.
The message sat in the Outbox after the rest of the
messages where sent. I then clicked on the message
and 'forwarded' it. That message was sent. When I then
tried to delete the original message in the 'Outbox'
folder, it will not allow it and gives me the following
message: 'This message interface has produced an unknown
error. If the problem persits, restart Outlook. When I
restarted Outlook (three times) the message still appears
when I try to delete it. Everything else works fine and
I can continue to send other messages and delete them.
Note: It will also not allow me to move the message.
HELP!