emails stuck in OUTBOX

[Tony]

I got 1 email stuck in the outbook:

(1) it has been sent and can be found in "SENT" box,
(2) but it still appear in "OUTBOX" and cannot be deleted (I tried many
times and said "unknown error:",

Now I cannot send other emails. All outgoing emails are stuck in the
"OUTBOX". Could someone help with this? Thank you.

 

[Gary VanderMolen]

Try this Microsoft fix:
http://support.microsoft.com/default.aspx/kb/941090

Incidentally, although it only mentions 'outbox', it works for all folders.