On Fri, Mar 11, 2011 at 04:58:15PM +0100, Giovanni Mancuso wrote:
> I have my postfix configured as MX record of my domain with particular
> smtpd_recipents_restriction, ecc...
> If my postfix receives a mail that has X-MyCustomHeader, Postfix accept
> the mail and delivers it to backend.
> If my Postfix receives a mail that hasn't X-MyCustomHeader, Postfix
> checks if client ip is in a blacklist and reject the email if the ip is
> in blacklist or accept the mail if it isn't in blacklist.
Rejection of email can only happen before the mail is queued. Therefore,
this can only be done with a proxy-filter or milter.
http://www.postfix.org/SMTPD_PROXY_README.html
http://www.postfix.org/MILTER_README.html
While client addresses can checked via built-in mechanisms in
smtpd_end_of_data_restrictions, there is no built-in mechanism to make
these checks dependent on the message headers. Adding such a feature
would not be easy, the header checks are performed in the cleanup(8)
server, while client address checks are performed in the smtpd(8)
server, the data flow from smtpd(8) to cleanup(8) is essentially
one-way...
http://www.postfix.org/OVERVIEW.html
--
Viktor.
