OT: Outlook oddities

[Steve Campbell]

Just wondering if anyone ever experiences email sent by Outlook senders 
that have no "From" in the envelop? The headers seem to have the proper 
"From" entry. These get caught quite often by MS (actually SA) with a 
"no watermark or sender address". They are sent from our users, which 
normally get whitelisted by IP address. The problem doesn't always 
happen even from the same sender.

Thanks and sorry for the OT

Steve Campbell