I am sure that if the MS product development team thought there was a reliable way of having Outlook differentiate between emails generated by other applications as a result of user actions that could not be mimicked by malware, they'd have done it.

The mere fact you don't like a security feature doesn't make it a bug. Live with it or employ a utility (such as that in the link) that exposes your system to exactly the kind of security risk the designed feature is meant to protect you and everyone in your email address book against.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]