Regarding the reverse dns on virtualmin for mail that is delivered as spam

[Stegan]

@jimr1

matter of time that email will be retired in favour of a new medium so these indicators maybe just resigned to history

shall I spend the next 1000 years gazing into my navel or crystal ball?
fortunately it will probably never happen.

[Joe]

Y’all are making this too complicated.

PTR should exist, it should resolve back to the same IP. That’s it.

Mail servers are not rejecting mail based on PTR not matching the HELO, that’s superstition, though you can make it match if that makes you happy. If you get SPF, DKIM, DMARC right, your mail will be delivered as reliably as it can be on an internet that is so overwhelmed with spam. Your IP might be on a bunch of blacklists; probably is on a bunch of blacklists if you just got it. That’s just how things are. You can probably get it unlisted if you put a few hours into making the request to all the major providers and RBLs. You can use a mail relay service in the meantime, if you need to send immediately and you’re finding your IP is poisoned…some have free tier.