sent emails stuck in outbox 2010.
this happened after I reinstalled the windows OS, I have 3 PST files which from my original OS.
to fix it:
go to control panel, change to small icon, mail(32bit),
high light the account had problem, change folder, create a new one,
then reopen outlook, let it run, then exit the outlook, change the folder back to the one you need.
done!
