Xie, Wei:
> Greetings,
>
> Our OSU State University uses Microsoft exchange servers as our
> main email system. Many users' email accounts are forwarding
> accounts, which forward emails of nam...@osu.edu<mailto:nam...@osu.edu>
> (i. e. smith.8...@osu.edu<mailto:smith.8...@osu.edu>) to other
> email systems such as gmail, yahoo, Hotmail, Buckeyemail, etc.
> Before these outbound emails are leaving from Ohio state university,
> they are scanned by our Security DLP (Data Loss Protection) servers
> on which MTA Postfix is running.
>
> Here we have a question about postfix. When the message passes by
> Postfix, can Postfix automatically add line "Resent-From: <OSU
> email address>" in the header?
How would Postfix know out that mail is forwarded from OSU Microsoft
exchange servers? Is it mail with a non-OSU envelope sender from a
system inside OSU? Must it also have a non-OSU envelope recipient?
If the rule is complex, then I recommend using an external content
filter. Amavisd-new supports policies that trigger on all kinds of
message properties. Postfix just an MTA.
Wietse
