Hi Doug,
Very much appreciate your response. In combination with Noel’s email, I think I get what’s going on now. All of this was, of course, in the service type section of http://www.postfix.org/master.5.html. Once I had an idea what I was looking for and gave it a slow re-read, it’s all there. As you said, the documentation is detailed and complete. I might add “in the extreme” but between that and the good samaritans on this list, the gap I was struggling with was handily bridged. :) Again, I really appreciate your feedback. Thanks, Scott ________________________________ From: Doug Hardie <bc...@lafn.org> Sent: June 9, 2020 6:02 PM To: Scott A. Wozny <sawo...@hotmail.com> Cc: postfix-users@postfix.org <postfix-users@postfix.org> Subject: Re: Questions about the master.cf file Having recently gone through this same confusion, perhaps some of what I figured out might help. The first column of the master.cf file is the port number for each of the ports that postfix will listen to, or the name of an internal postfix process. In the distributed file, the names from the /etc/services file are used rather than the port numbers. For example, smtp is port 25. However, looking down you will see one line for port 628 (commented out though). The last argument on each line tells postfix which process to send the request to. Thats why postscreen replaces the smtp line with the postscreen process. Postscreen is smart - it injects messages into the system by sending them to smtpd. There is an entry for smtpd (the postfix process) that lets you add restrictions for smptd. Here is a portion of my master.cf: smtpd pass - - n - 50 smtpd -o smtpd_recipient_restrictions=$incoming_smtpd_restrictions smtp inet n - n - 1 postscreen dnsblog unix - - n - 0 dnsblog tlsproxy unix - - n - 0 tlsproxy submission inet n - n - 10 smtpd -o smtpd_recipient_restrictions=permit_sasl_authenticated,reject -o syslog_name=postfix-submission dovecot unix - n n - - pipe flags=DRhu user=vmail:vmail argv=/usr/local/libexec/dovecot/dovecot-lda -f ${sender} -d ${recipient} I use macros defined in main.cf for the restrictions on port 25 (smtp after postscreen) and port 587 (submission). dnsblog and tlsproxy are internal postscript processes. dovecot is a local delivery via dovecot. It's a bit difficult at first to see the forrest through the trees as the documentation is detailed and complete. However, once you discover the forrest, then the documentation will be quite helpful. -- Doug
