Paul Grossman wrote:

I have 5 accounts set up.

This, I think, may be the magic answer. When Outlook 2007 came out, there
was a problem with it such that it it would appear to send extra messages,
where the extra number depended on the number of accounts you have. This
problem was reported in these newsgroups in September. I don't recall if a
solution was ever found or what the cause might have been. See these
threads:
http://groups.google.com/groups/search?q=group%3Amicrosoft.public.outlook.*+%2B200 7+%2Bsending+%2Bextra+%2Bmessages

You could see how many tried Outlook is making by enabling diagnostic
logging and examining the SMTP portion of the log.
http://support.microsoft.com/kb/831053/en-us
--
Brian Tillman [MVP-Outlook]