Cannot send outlook 2003 email from other application

[Beemer]

I use Photo Mechanic which is a digital photograph browser. I select an on
screen photograph and the program prepares an Outlook send message with the
jpg photograph as an attachment. However when I hit the message send button
I get "Unable to send this item" error message. I have tried this with
Outlook 2003 running and without but the error is the same.

My Outlook 2003 is otherwise working perfectly with only one personal folder
and I do not use MAPI only standard smtp pop3.

I have read the MS support pages on this error but I see nothing which will
solve this.

Anyone know how to fix this?

Beemer