> What are the $mua_helo_restrictions and $mua_sender_restrictions in the > master.cf
http://www.postfix.org/master.5.html -o name=value (short form) Override the named main.cf configuration parameter. The parameter value can refer to other parameters as $name etc., just like in main.cf. See postconf(5) for syntax. ``smtpd_sender_restrictions`` and other options may be different for public SMTPD and smtpd used by clients (mua) So, you specify variable "mua_helo_restrictions" in your ``main.cf`` and provide it as an option to the smtps. > How do they affect the restrictions for the submission if left commented ? Smtpd server uses ``smtpd_sender_restrictions`` and other options. See : http://www.postfix.org/postconf.5.html#smtpd_sender_restrictions But if you add ``-o smtpd_sender_restrictions=$my_fancy_new_restrictions`` it will use value of this variable instead of ``smtpd_sender_restrictions`` If you have several SMTPD servers (the public one and the one used for submission) you may want them to have different settings.
