On Tue, Nov 10, 2015 at 01:29:43PM +0100, Zalezny Niezalezny wrote: > I would like to understand how Postfix receiving message. I expect that > Postfix has been written base on the RFC rules so maybe somebody will be > able to explain me how its working inside - how this system receiving > message and what is going on in the background.
You need to ask a more concrete question. It is unlikely that anyone will post a comprehensive architecture overview of Postfix, or a detailed walk-through of the multiple relevant email RFCs. You can read the Postfix book by Patrick Koetter and Ralf Hildebrandt, and the multiple documents at: <http://www.postfix.org/documentation.html>. http://www.postfix.org/OVERVIEW.html http://www.postfix.org/SMTPD_ACCESS_README.html http://www.postfix.org/postfix-manuals.html http://www.postfix.org/smtpd.8.html > Our consultant hardly trying to tell us that server during receiving phase > checking MX record of the domain from which coming the E-mail. Does it > really working this way ? I always thought that Postfix checking first DNS > A record (reverse dns), then SPF etc.etc. If you're having a problem receiving mail, post the relevant logs and information about your configuration as described in: http://www.postfix.org/DEBUG_README.html#mail and explained in the Welcome message you received when you joined the list. > Does system check mx record when its receiving message or not? Only if you configure Postfix to do that, directly or indirectly. > Do You know where may I find RFC which fully describing this SMTP process? There is no single RFC that describes everything SMTP servers do behind the scenes when receiving messages, even the entire collection of email-related RFCs is properly silent on many implementation-specific and local policy issues. http://www.faqs.org/rfcs/np.html#SMTP http://www.faqs.org/rfcs/np.html#Other -- Viktor.
