Email, PTR records, and reverse DNS on EC2

My web server IP has been added to the "Abusix Mail Intelligence Policy list". This is apparently because

"This blacklist lists all IP addresses that are unlikely to be used by a legitimate mail server. Legitimate mail servers should use a static IP address with a non-generic PTR record and that reflect the host and domain name of the mail server and ideally should match the forward lookup for the same name. This list is generated by running a reverse DNS lookup for every IPv4 IP address and lists IPs with:

no PTR record

PTR record with an invalid top-level domain (TLD)

PTR record contains part of the IP address (e.g. 127-0-0-1.example.com)

PTR indicates dynamic IP (e.g. subdomain contains: dynamic, dyn, cable, generic-host, nothing, dsl, dial, dhcp, unallocated, broadband, internetdsl, gprs, no-dns-yet, unassigned, unknown, ipngn, ...)

"

My IP address has a PTR record created by AWS, as below - IP changed obviously. As the IP address is in the PTR record it's been added to this list.

ec2-52-1-1-1.us-west-2.compute.amazonaws.com

I host about half a dozen domains on the server. I host my email on FastMail, so the only email that comes out of the server is notifications to me.

Should I add a PTR record to the main domain for the server? How about for every other domain on the server? It's fairly easy to get AWS to remove their PTR record.

I have already requested a delist - I'm just making sure I get the DNS set up properly.