#rev 2018-11-22 maegger
#rev 2020-09-04 maegger

= Postfix Restrictions =
Postfix offers a lot of restriction possibilities to allow or block connections.
 * [[http://www.postfix.org/postconf.5.html#smtpd_relay_restrictions|smtpd_relay_restrictions]] - Access restrictions for mail relay control (who can relay?).
 * [[http://www.postfix.org/postconf.5.html#smtpd_helo_restrictions|smtpd_helo_restrictions]] - Optional restrictions that the Postfix SMTP server applies in the context of a client HELO command.
 * [[http://www.postfix.org/postconf.5.html#smtpd_restriction_classes|smtpd_restriction_classes]] -  User-defined aliases for groups of access restrictions. One major application is for implementing per-recipient UCE control.
 * [[http://www.postfix.org/postconf.5.html#smtpd_recipient_restrictions|smtpd_recipient_restrictions]] - Optional restrictions that the Postfix SMTP server applies in the context of a client RCPT TO command, after smtpd_relay_restrictions.
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[[CategoryMAIL]]