Reverse DNS with other sites.

[systimax]

Hello, I am dealing with a site that has GWIA 6.0x.

They have turned on Reverse DNS.

We have reverse (ptr records for all or servers but are still getting blocked. I believe this is the situation.


Hello, I am having issues with other companies using reverse DNS lookups on there mail server. I’m getting blocked.

1. The problem is that I send an email to my internal email server

2. It then goes to a internal mail gateway/virus scanner on the DMZ

3. The Mail Gateway then sends the message from the DMZ to the external interface of the firewall and gets the ip address stamped on it (NAT).

3. When connecting to the remote server (Groupwise Internet Agent) the remote server does a reverse lookup. I think its trying to match the sender’s mail domain in the headers to the IP address of the sender. That I’m not sure

4. Either way It fails because the its resolving the firewalls IP address. And not the Public IP of our mail server or MX IP

I'm not sure what it is trying to reverse but its failing since its getting the firewall ip.


Anyone have any thoughts?

 

[rjs]

If you have a PTR record for the firewall IP address, it should not be a problem.

 

[systimax]

Like i said I do already have all PTRs