Does anyone know if it is possible to have reverse dns entries for virtual hosts? I don't see how it would be possible because one IP would need to resolve to multiple domains.

When I check out any of my domains on dnsreport.com I get:

FAIL Reverse DNS entries for MX records ERROR: One or more of your mail server(s) have no reverse DNS (PTR) entries (if you see "Timeout" below, it may mean that your DNS servers did not respond fast enough). RFC1912 2.1 says you should have a reverse DNS for all your mail servers. It is strongly urged that you have them, as many mailservers will not accept mail from mailservers with no reverse DNS entry. You can double-check using the 'Reverse DNS Lookup' tool at the DNSstuff site. The problem MX records are:
88.169.22.69.in-addr.arpa [No reverse DNS entry (rcode: 2 ancount: 0)]


Is this going to be a problem, or is this common?

Thanks!

The reverse dns is only for the server hostname and not for every domain.

If you don't have reverse dns on your servers, your domains will also have no reverse dns entries, and all domains on the servers will be the same. You need to ask your isp toset it for you