Outlook 2003 - advising of Automatic Email

[Volleyball Charlie]

My system has Outlook Express set as the default mail system.
I use Outlook 2003 for personal emails, and Outlook Express handles messages
from my Database.
After a recent update from Microsoft, as always I have to switch Outlook
Express back to the default, but in addition when the database sends a simple
acknowledgement with the Send command, I keep getting Outlook 2003
interfering and telling me that a possible virus is sending automatic emails.
I do not want that happening, it was not happening yesterday.
Can some explain how to switch it off.

Thanks

Charlie Orton