Hello all,
here is my problem:
I have several hosting servers, sending mails from authenticated users,
web scripts, web pages, and so on... I cannot monitor everything, and
our greatest problem is outgoing unauthorized mails. we experience
10'000 mails spam campaigns every week or so... No need to says that
this is no good for blacklisting.
As I have root access everywhere, I can construct an exhaustive list of
allowed sender domains.
Then I build up a new mail gateway dedicated to outgoing mails, and
configure it as follows:
smtpd_sender_restrictions =
check_sender_access hash:/etc/postfix/sender_access
reject_unverified_sender
warn_if_reject
reject
Now I get a warning in my logs every time a potentially unauthorized
mails goes out.
But I can't have any visibility over redirected mails. We've got several
users that configure their mailbox to resend their email on another
external mailbox, and we do not want to consider this kind of mail as
"unwanted"!
I have seen nothing and everything about this kind of mail, and I wonder
if postfix is by any way able to detect this kind of mail...? The real
problem, as I understand it, is that I want to configure this Postfix as
an independant server, that would be the "relayhost" of all our hosting
servers...
If anyone could lead me to enlightenment here...
Thanks in advance!
Simon
