Postfix -> How stop forged MAIL FROM: for authenticated users

[pititis]

Hi,

Frist,

add to main.cf :

smtpd_sender_login_maps = regexp:/etc/postfix/login_maps.regexp
smtpd_sender_restrictions = reject_authenticated_sender_login_mismatch, ...

where ... are the rest of options for smtpd_sender_restrictions

Second:

Create the file /etc/postfix/login_maps.regexp and add inside:

/^(.*)$/

and.. reload postfix

Now if an authenticated user try to change MAIL FROM:, will get:

connect from xxx[xxx]
Dec 28 17:46:35 server postfix/smtpd[2238]: NOQUEUE: reject: RCPT from xxx[66.66.66.66]: 553 5.7.1 <info@domain.com>: Sender address rejected: not owned by user admin@otherdomain.com; from=<info@domain.com> to=<webmaster@example.com> proto=ESMTP helo=<xxxt>

Cheers