Outlook continually tries to resend mail that has already been sent.  The
outbox is empty; however, every minute an attempt is made to send no longer
existent mail.  This often prevents me from being able to send new mail.  I
have to exit Outlook, go back in and then it will send my new mail, followed
by long attempts to send mail that is NOT there.  The error message that
originally appeared said to contact network administrator (it's just me and
my laptop) or my ISP.  I have contacted Verizon twice.  They don't seem to
understand the problem.  Their people have connected to me remotely and only
made things worse and never solved the problem.  They run mail sending tests,
then tell me the problem is solved (and it's not).  I can receive mail just
fine, by the way.