>>> #
>>> # Initialize.
>>> #
>>> #! ../bin/postmap smtpd_check_access
>>> #msg_verbose 1
>>> #smtpd_delay_reject 0
>>> #mynetworks 127.0.0.0/8,168.100.189.0/28
>>> #relay_domains porcupine.org
>>> #maps_rbl_domains dnsbltest.porcupine.org
>>> #rbl_reply_maps hash:smtpd_check_access
>>> #helo foobar
>>> #
>>> # reject_unknown_helo_hostname
>>> #
>>> smtpd_delay_reject 0
OK
>>> helo_restrictions reject_unknown_helo_hostname
OK
>>> client spike.porcupine.org 168.100.189.2
OK
>>> mail sname@sdomain
OK
>>> rcpt rname@rdomain
OK
>>> helo nxdomain.porcupine.org
./smtpd_check: <queue id>: reject: HELO from spike.porcupine.org[168.100.189.2]: 450 4.7.1 <nxdomain.porcupine.org>: Helo command rejected: Host not found; from=<sname@sdomain> proto=SMTP helo=<nxdomain.porcupine.org>
450 4.7.1 <nxdomain.porcupine.org>: Helo command rejected: Host not found
>>> helo nullmx.porcupine.org
OK
>>> helo spike.porcupine.org
OK
>>> #
>>> # reject_unknown_sender_domain
>>> #
>>> smtpd_delay_reject 0
OK
>>> sender_restrictions reject_unknown_sender_domain
OK
>>> client spike.porcupine.org 168.100.189.2
OK
>>> helo spike.porcupine.org
OK
>>> rcpt rname@rdomain
OK
>>> mail sname@nxdomain.porcupine.org
./smtpd_check: <queue id>: reject: MAIL from spike.porcupine.org[168.100.189.2]: 450 4.1.8 <sname@nxdomain.porcupine.org>: Sender address rejected: Domain not found; from=<sname@nxdomain.porcupine.org> proto=SMTP helo=<spike.porcupine.org>
450 4.1.8 <sname@nxdomain.porcupine.org>: Sender address rejected: Domain not found
>>> mail sname@nullmx.porcupine.org
./smtpd_check: <queue id>: reject: MAIL from spike.porcupine.org[168.100.189.2]: 550 5.7.27 <sname@nullmx.porcupine.org>: Sender address rejected: Domain nullmx.porcupine.org does not accept mail (nullMX); from=<sname@nullmx.porcupine.org> proto=SMTP helo=<spike.porcupine.org>
550 5.7.27 <sname@nullmx.porcupine.org>: Sender address rejected: Domain nullmx.porcupine.org does not accept mail (nullMX)
>>> mail sname@spike.porcupine.org
OK
>>> #
>>> # reject_unknown_recipient_domain
>>> #
>>> smtpd_delay_reject 0
OK
>>> sender_restrictions permit
OK
>>> recipient_restrictions reject_unknown_recipient_domain
OK
>>> relay_restrictions reject_unauth_destination
OK
>>> client spike.porcupine.org 168.100.189.2
OK
>>> helo spike.porcupine.org
OK
>>> mail sname@sdomain
OK
>>> relay_domains nxdomain.porcupine.org
OK
>>> rcpt rname@nxdomain.porcupine.org
./smtpd_check: <queue id>: reject: RCPT from spike.porcupine.org[168.100.189.2]: 450 4.1.2 <rname@nxdomain.porcupine.org>: Recipient address rejected: Domain not found; from=<sname@sdomain> to=<rname@nxdomain.porcupine.org> proto=SMTP helo=<spike.porcupine.org>
450 4.1.2 <rname@nxdomain.porcupine.org>: Recipient address rejected: Domain not found
>>> relay_domains nullmx.porcupine.org
OK
>>> rcpt rname@nullmx.porcupine.org
./smtpd_check: <queue id>: reject: RCPT from spike.porcupine.org[168.100.189.2]: 556 5.1.10 <rname@nullmx.porcupine.org>: Recipient address rejected: Domain nullmx.porcupine.org does not accept mail (nullMX); from=<sname@sdomain> to=<rname@nullmx.porcupine.org> proto=SMTP helo=<spike.porcupine.org>
556 5.1.10 <rname@nullmx.porcupine.org>: Recipient address rejected: Domain nullmx.porcupine.org does not accept mail (nullMX)
>>> relay_domains spike.porcupine.org
OK
>>> rcpt rname@spike.porcupine.org
OK
>>> #
>>> # check_mx_access
>>> #
>>> smtpd_delay_reject 0
OK
>>> sender_restrictions check_sender_mx_access,hash:smtpd_check_access
OK
>>> client spike.porcupine.org 168.100.189.2
OK
>>> mail sname@nxdomain.porcupine.org
./smtpd_check: warning: Unable to look up MX host nxdomain.porcupine.org for Sender address sname@nxdomain.porcupine.org: hostname nor servname provided, or not known
OK
>>> mail sname@nullmx.porcupine.org
OK
>>> mail sname@spike.porcupine.org
./smtpd_check: <queue id>: reject: MAIL from spike.porcupine.org[168.100.189.2]: 554 5.7.1 <sname@spike.porcupine.org>: Sender address rejected: ns or mx server spike.porcupine.org; from=<sname@spike.porcupine.org> proto=SMTP helo=<spike.porcupine.org>
554 5.7.1 <sname@spike.porcupine.org>: Sender address rejected: ns or mx server spike.porcupine.org