Hi,
I have a mail filter setup for my exchange server. Incoming email goes to a postfix box with postgrey/amavis/spamassassin/antivirus and then forwards to my exchange server.

the forwarding is done by relay_domains in main.cf with a corresponding entry in transport

What I would like to do, is have a file with "accepted" email addresses.

my problem is backscattering. a spoofed message comes in. goes through greylisting, spam filtering and gets delivered to exchange. exchange then bounces the email as the user doesn't exist. This goes out as a new message and hits the mailserver for the spoofed email and gets bounced back to us. We get put on a RBL for the amount of bounces.

So I want the content filter to only accept mail for known users.
I don't know if I can setup postfix as a "virtual domain" server and still forward the mail to exchange

thanks

Just to address the last line of your post, according to the Postfix documentation you can set up an address verification list/database, for recipients:
http://www.postfix.org/ADDRESS_VERIF...html#recipient
http://www.postfix.org/LOCAL_RECIPIENT_README.html

Thanks,
I will read through those pages and see how they will work for me.

I am thinking that check_recipient_access=hash:/etc/postfix/recipient_list

where /etc/postfix/recipient_list contains

user1@domain.com OK
user2@domain.com OK
domain.com REJECT

postmap /etc/postfix/recipient_list

might just do it. I have exported a list of addresses from exchange and wrote a program to convert the csv to a file in the above format.

Thoughts?

I'm not sure whether this link below will help.


http://serverfault.com/questions/623...poofed-senders