Outlook2003 keeps sending sent messages, also tries to send something I dont see

[elmer]

I am running WinXP SP2, Office 2003 with Outlook 2003. I am the only user and I run under full administrator rights.
This is what happens:
 First part : When I send an email, sometimes it stays in the "emails to be sent" folder and keeps being sent until I delete it. 
 Second part: Even with the "emails to be sent" folder empty, the outlook shows that it is sending some two emails all the time, I have no idea what is it trying to send. It always shows an arreor mesage at the end. My guess is it has some information stored somewhere that there are emails waiting for being sent, but I cant find that...
All help will be very much appreciated. Thank you.

[patio]

It's possible your machine has been compromised.

Please list all the protection programs you currently have and when you scanned / updated last...

[soybean]

First part : When I send an email, sometimes it stays in the "emails to be sent" folder and keeps being sent until I delete it. 

Outlook has no "emails to be sent" folder unless you created it.  It does have an Outbox folder.  Do you mean the Outbox?

If you go to Tools, Options, Mail Setup, is the box for "Send immediately when connected" checked?

[GX1_Man]

Are these just text mails or large files with attachments?

[Raptor]

It may fail to send them and is waiting for you to fix the problem but it'll keep retrying.. How about some error logs?

[patio]

The light grows dimmer...