Hi!

I have an sendmail server, sitting in front of my Exchange server. This server filter spam with SpamAssassin (and do it incredibly well!), but it merely tag spam messages with appropriate header flags and by modifying message subject. When such a message arrives to user mailbox on Exchange server, where it is examined by Echange/Outlook junk e-mail filter, which put most of spam in junk message folder.

And that is my problem: most, but not all! To put all spam in junk e-mail message folder, user has to define an rule, saying f.e:

"If header contains text 'X-Spam-Flag: YES' then move it to 'Junk e-mail messages' folder".

Fine, but it has to be done on every user (for some users, this task is too "complicated" to made it themselves :-) .

So I want to know, how could I modify message header in such a way, that Exchange junk e-mail filter will for 100% recognize this message as a spam, freeing user from task of defining his own rule.

Some solution could be defining such a rule by using AD and group policy, but I wan't to avoid this due to many possible caveats: there are so many combination of different operating system and different Outlook versions, and to be honest, I doubt if it is even possible.