My setup does the same, I don't know why it is - if its a bug or a setting
orjust the way outlook works. If I try to close Outlook it warns me that
therer are unsent messages in my outbox. I just hit the send/recieve button
that is situated in the inbox folder.
I think it is a setting that lets you write a bunch of emails, store them in
the "outbox" and send them when you next hook up to the internet. Bit of a
hangover from the days when dialup was more usual than broadband. In that era
the computer might not be connected to the internet and it would then dial
internet every time you pushed the send button.
I rekon you can probably change the settings but I don't know where.