Hello all, I stumbled upon a weird situation when trying to send mail to [email protected]. smtpd entered into an endless loop:
——————————————————————————————————————————— obsd-test# mail -s test [email protected] test . EOT obsd-test# Feb 17 16:00:01 obsd-test smtpd[74143]: f63245c93259f11c smtp connected address=local host=obsd-test.rebehn.net Feb 17 16:00:01 obsd-test smtpd[74143]: f63245c93259f11c smtp message msgid=7157a411 size=363 nrcpt=1 proto=ESMTP Feb 17 16:00:01 obsd-test smtpd[74143]: f63245c93259f11c smtp envelope evpid=7157a411f91aaef7 from=<[email protected]> to=<[email protected]> Feb 17 16:00:01 obsd-test smtpd[74143]: f63245c93259f11c smtp disconnected reason=quit 2023-02-17T15:00:01.986Z obsd-test newsyslog[87010]: logfile turned over tail: /var/log/maillog has been replaced, reopening. 2023-02-17T15:00:01.986Z obsd-test newsyslog[87010]: logfile turned over Feb 17 16:00:02 obsd-test smtpd[74143]: f63245cd0d08e264 mta connecting address=smtp://127.0.0.1:25 host=localhost Feb 17 16:00:02 obsd-test smtpd[74143]: f63245cd0d08e264 mta connected Feb 17 16:00:02 obsd-test smtpd[74143]: f63245ce7265d1ed smtp connected address=127.0.0.1 host=localhost Feb 17 16:00:02 obsd-test smtpd[74143]: f63245ce7265d1ed smtp message msgid=d2ff5ca2 size=546 nrcpt=1 proto=ESMTP Feb 17 16:00:02 obsd-test smtpd[74143]: f63245ce7265d1ed smtp envelope evpid=d2ff5ca2aa40c428 from=<[email protected]> to=<[email protected]> Feb 17 16:00:02 obsd-test smtpd[74143]: f63245cd0d08e264 mta delivery evpid=7157a411f91aaef7 from=<[email protected]> to=<[email protected]> rcpt=<-> source="127.0.0.1" relay="127.0.0.1 (localhost)" delay=1s result="Ok" stat="250 2.0.0 d2ff5ca2 Message accepted for delivery" Feb 17 16:00:03 obsd-test smtpd[74143]: f63245ce7265d1ed smtp message msgid=209c5192 size=729 nrcpt=1 proto=ESMTP Feb 17 16:00:03 obsd-test smtpd[74143]: f63245ce7265d1ed smtp envelope evpid=209c519220fca0c2 from=<[email protected]> to=<[email protected]> Feb 17 16:00:03 obsd-test smtpd[74143]: f63245cd0d08e264 mta delivery evpid=d2ff5ca2aa40c428 from=<[email protected]> to=<[email protected]> rcpt=<-> source="127.0.0.1" relay="127.0.0.1 (localhost)" delay=1s result="Ok" stat="250 2.0.0 209c5192 Message accepted for delivery" Feb 17 16:00:04 obsd-test smtpd[74143]: f63245ce7265d1ed smtp message msgid=2f497747 size=912 nrcpt=1 proto=ESMTP Feb 17 16:00:04 obsd-test smtpd[74143]: f63245ce7265d1ed smtp envelope evpid=2f497747f408bbd3 from=<[email protected]> to=<[email protected]> Feb 17 16:00:04 obsd-test smtpd[74143]: f63245cd0d08e264 mta delivery evpid=209c519220fca0c2 from=<[email protected]> to=<[email protected]> rcpt=<-> source="127.0.0.1" relay="127.0.0.1 (localhost)" delay=1s result="Ok" stat="250 2.0.0 2f497747 Message accepted for delivery” etc... —————————————————————————————————————————————— The reason for this is: obsd-test# host webmail.de webmail.de has address 64.190.63.111 webmail.de mail is handled by 0 localhost. I mistyped swbmail.de as webmail.de. So it is partially my fault. Webmail.de is for sale by sedo.com. It is really weird that they enter localhost as mx. They should at least have their own fake mailer which simply rejects emails to webmail.com. But my question is: How can I harden smtpd.conf against such mx entries? OpenBSD obsd-test.rebehn.net 7.2 GENERIC#6 amd64 running under ESXi 7.0U3 Clean install, default smtpd.conf Thanks for any help, Heinrich
