>>>>> "JR" == Jaroslaw Rafa <r...@rafa.eu.org> writes:
JR> Dnia 3.12.2021 o godz. 09:14:23 Fourhundred Thecat pisze: >> Hello, >> >> I have strict helo checks: >> >> smtpd_helo_required = yes smtpd_helo_restrictions = >> reject_non_fqdn_helo_hostname, reject_invalid_helo_hostname, >> reject_unknown_helo_hostname >> >> now I have noticed mails being rejected: >> >> Helo command rejected: Host not found >> >> warning: hostname mail-eopbgr80085.outbound.protection.outlook.com does not >> resolve to address 40.107.8.85: Name or service not known JR> reject_unknown_helo_hostname is known to produce quite a lot of false JR> positives, and it is not recommended to use this restriction. The postfix main.cf documentation says for reject_unknown_helo_hostname: "Reject the request when the HELO or EHLO hostname has no DNS A or MX record. " http://www.postfix.org/SMTPD_ACCESS_README.html has a comment # Don't talk to mail systems that don't know their own hostname. # With Postfix < 2.3, specify reject_unknown_hostname. smtpd_helo_restrictions = reject_unknown_helo_hostname I am confused care to elaborate.
