I'm confused where is the RDNS setup at? The reason I ask for is because one of our providers set up PTR directly through the DNS zone. When running a RDNS check on our IP's they redirect to the proper domain. Well another one of our providers said they setup a rDNS, but I didn't see any PTR entries under the DNS zone. The issue is that when we do a rDNS check on our IP's it shows server.ourdomain.com (the same for all IP"s)... I'm just a bit confused here.. Are we able to add the PTR entry ourself or does our hosting provider have to do this?
I would recommend you allow your web hosting provider take care of that. That is what they are paid for.
You can see who would be authoritative for a reverse record if you do a NS query against the ARPA zone, for example: www.yahoo.com 67.195.160.76 22:32:19-zach@ninja:~$ dig +short ns 160.195.67.in-addr.arpa. ns1.yahoo.com. ns2.yahoo.com. ns3.yahoo.com. ns4.yahoo.com. ns5.yahoo.com. If you see your own nameservers in there, then you probably have delegated RDNS control, otherwise that's something you'll have to ask your hosting provider to do.
rDNS and PTR are the same thing, just different names. Like Kleenex and tissues. As others have said, these are setup by your hosting provider. You'll have to contact them if you want an rDNS record added, these are required for mail servers.