Multiple server names on one server possible?

I can't be the only one with rDNS problems ...

[internetheaven]

I have 50 websites hosted across 4 IPs on a Plesk Onyx server. However, all email addresses for the websites not hosted on the main server IP address are getting "rDNS doesn't match" errors when trying to email people. Obviously:

[e-mail] hosted on 11.22.33.44 returns name.server.net which rDNS gives back 11.22.33.44

However:

[e-mail] hosted on 11.22.33.45 also returns name.server.net which rDNS gives back as 11.22.33.44
[e-mail] hosted on 11.22.33.47 also returns name.server.net which rDNS gives back as 11.22.33.44
etc.

Can you give each IP address on a server it's own nameserver? How does everyone else get around this rDNS problem? I'm clearly not the only person with multiple IPs on a server. But I can't find an answer anywhere and I've been at this all day! (And that's after all day yesterday trying to sort the DKIM problems!)

Help, please?
Thanks

[robzilla]

Every IP address can have its own PTR record, but you cannot attach the same hostname to multiple IP addresses in your DNS records. After all, while it's possible for multiple IP addresses to have the reverse DNS record set to the same hostname, a forward DNS query for that hostname can only return one IP address. You will need to contact your host to change the rDNS of your other IP addresses to something unique like name2.server.net, name3.server.net, and then you should set up forward DNS records for those hostnames (e.g. point "name2" A record to the corresponding IP address).