Issues with smtp-banner. Contact the provider or is it on my side?

Question

Mail server

Hello.
When testing the smtp server, it says that the smtp banner does not match the reverse rDNS record.
"Smtp banner [220-gate-yak.mydomain.ru] does not match rDNS IP address".
rDNS at the provider is written as: "gate-yak.mydomain.ru". But Postfix installed on pfsense adds "220-" before the banner, even if I force smtp banner in "custom main.cf options".
I don’t quite understand, should I contact the provider and ask him to change the rDNS record to 220-gate-yak.mydomain.ru? (Then will the helo and ehlo responses of this server be correct) Or is this a problem on my side, in that case?

Answer 1

This usually happens when the commands
host 1.2.3.4
and
host nichego.net
(where instead of 1.2.3.4 - your IP, and instead of nichego.net - your domain name) return a different result, although they should be the same. One of the very first anti-spam checks. You need to contact the provider with a request to change the PTR record in the reverse zone - register nichego.net there instead of auto-generated garbage.