I'm currently trying to figure out how to configure my rDNS to be SpamAssassin friendly.
SpamAssassin's documentation only seems to provide the following;
"The HELO appeared to be suspicious. This is typically the result of a poorly configured email server advertising itself as XXX-XXX-XXX-XXX.hostname.tld (where XXX is an IP address)."
Currently, my rDNS is set as follows on the ISP's side;
domainname obviously being my domain name. Originally, it was that but without the "static" part, I tried doing this as the documentation on what is an acceptable "static" and "non-generic" rDNS would be. Didn't seem to fix the issue. I've also tried using the following service; https://www.debouncer.com/reverse-dns-check
I'm currently Postfix/Dovecot on FreeBSD, and using cloudflare for my DNS (Exclusively in DNS only mode as cloudflare itself doesn't support email traffic), I've set up an A record to point my reverse DNS towards my server's IP so that it resolves.
What should I do to mitigate this issue? My guess currently would be to remove the IP entirely from the rDNS record.