Hi,
My Postfix setup works quite well blocking most spam. But I sometimes
get spam with (to my untrained eye) valid MAIL from: and RCPT to: email
addresses but in the DATA section there is a forged From:
<m...@mydomain.com>. At least that's how it works when I use telnet to
port 25 on my Postfix box.
I tried the example header_checks [1] from the BACKSCATTER_README which
work fine except that they also block my own email. What is the proper
way to block forged From: addresses in the DATA section?
Thanks for any pointers or which FMTR.
Regards,
Patrick
/etc/postfix/header_checks:
/^(From|Return-Path):.*\b(user@domain\.tld)\b/
reject forged sender address in $1: header: $2
