A question from a beginner Postfix admin.
What is the exact difference between writing in main.cf
:
smtpd_reject_unlisted_sender = yes
and
smtpd_sender_restrictions =
reject_unlisted_sender
?
Is there a real difference in operation or is smtpd_reject_unlisted_sender
just a way to enforce this restriction when some of rules listed in smtpd_sender_restrictions
results in PERMIT
?
The first option apply to all local senders, the second permit to have a criteria like:
on file /etc/postfix/acl_unknown_permited
The 'permit' inside /etc/postfix/acl_unknown_permited make restriction process jump to smtpd_recipient_restriction without process reject_unlisted_sender. The right hand of file support a acl list, like:
This create many possiblilities.