Ip went to spam. How to determine what?

Question

Fight against spam

Hello. There are two domains expolesdv.ru and expolinedv.ru tied to the same ip. Behind this ip stands Exchange.
A couple of days ago this ip started getting into spam lists.
I do not find any suspicious traffic inside the network.
When checking, mxtoolbox writes a single error Primary Name Server Not Listed At Parent. Can it be added to the spam list? And I understand that the problem is on the hosting side? Googling says that it seems to be a problem with the SOA record, and when checking on the 2ip site, we see that expolinedv is missing the ;; AUTHORITY SECTION:, but when checking from a computer dig expolinedv.ru -t SOA this entry appears. Maybe this is the problem?

In general, the question is: how to find the reason why we got into the spam lists? I don't know where to look anymore...

Answer 1

If you know exactly which spam lists you got into, go to their site and check. All more or less large list operators have both a self-check and a small help on what to do, and sometimes even a "Delete me" button