I see lots of messages getting rejected for one of my domains (secondary MX) with the following information:
"No IP address found for HELO smtp.conn, try again later"
What does that mean?
No IP address found for HELO smtp.conn, try again later
Moderator: Moderators
Re: No IP address found for HELO smtp.conn, try again later
That message is from one of the client validity checks:
https://acc.rollernet.us/help/mail/client.php
Specifically, the "HELO must resolve to client IP" test, which is a stricter form of the "HELO must resolve to any IP" test. The message means the client sent a HELO/EHLO that did not resolve even though RFC 5321 section 2.3.5 states that it MUST be a primary host name, i.e. resolvable.
https://acc.rollernet.us/help/mail/client.php
Specifically, the "HELO must resolve to client IP" test, which is a stricter form of the "HELO must resolve to any IP" test. The message means the client sent a HELO/EHLO that did not resolve even though RFC 5321 section 2.3.5 states that it MUST be a primary host name, i.e. resolvable.
Seth Mattinen, Roller Network LLC