Thank You for all previous answers.
We have two systems which are dedicated only to send E-mails. Mostly for massmailing. These two machines will not receive any E-mails. Do we realy need to configure MX records for that systems if they are not receiving any E-mails ? From my point of view checking MX record from the client which sending message is ... strange... if not stupid... In the SPF record we can have a lot of systems which are not necesserly configured in the MX record. Does it realy make sense ? On Tue, Nov 10, 2015 at 6:32 PM, Viktor Dukhovni <postfix-us...@dukhovni.org > wrote: > 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. >
