I have visited the AOL site re: reverse DNS requirements. Our ISP made the following change since no “test.com” domain reference existed. Does anything appear wrong? It lists the server’s actual hostname.domainname (server.test.com) vs. test.com associated with all outgoing mail (user@test.com). Could this be causing an issue? Does mail have to be relayed to the firewall in this case? We prefer for it to go out directly.
Host Type Value
210.15.33.62.in-addr.arpa PTR server.test.com
15.33.62.in-addr.arpa NS ns1.isp.net
15.33.62.in-addr.arpa NS ns2.isp.net
15.33.62.in-addr.arpa NS ns3.isp.net
ns1.isp.net A 66.176.96.11
ns2.isp.net A 64.236.96.11
ns3.isp.net A 64.234.96.9
If I telnet on port 25 to *.210, I get an SMTP response from the firewall vs. server.test.com. Thanks…
I used an online DNS tool and received this error…
210.15.33.62 PTR record: server.test.com. [TTL 3600s] [A=None] ERROR A record does not point back to original IP.
Is an A record required for this server?
Subject: AOL & Reverse DNS Issue? No Messages Outbound
Can you provide more info? Are you going directly? Or is it NATing out through the firewall? In any event if you go out directly and you connect to AOL.COM (among others) you need to ensure that a reverse dns query on the IP of address as seen by the target SMTP is valid.
Since you used an online dns tool, you can see that your IP address doesn’t have a PTR record. You need to contact the block owner of the IP address which is most likely your ISP, tell them your IP address and what you’d like the reserve dns lookup to resolve to.
So if you are saying it is server.test.com, then tell them lookups to 210.15.33.62 should resolve to server.test.com for a PTR lookup.
They should gladly accomdate it. Give it 24 hours, or in the case of AOL which caches everything for about 3 days or so, 72 hours.
Mike Robinson
http://www.invcs.com
Subject: RE: AOL & Reverse DNS Issue? No Messages Outbound
Thanks! I did a couple other tests… accessed an external mail server and noted that the IP connecting (SMTP) is *.212 instead of the *.210 listed in the PTR. Mail goes out directly (no relay) but comes in via test.com and is then routed to server.test.com. In this case, should the PTR still have server.test.com (and *.212) since inbound SMTP connections to test.com are not handled initially by server.test.com? First thought… outbound mail domain is test.com (e.g. user@test.com is sending mail to AOL). Should the PTR really be test.com? …or does AOL extract the server.test.com at connection time? It might just be the *.212 setting. A lookup might work… but no ping/telnet could be establish. WOuld server.test.com still need an A record to compliment the PTR?
Subject: RE: AOL & Reverse DNS Issue? No Messages Outbound
I believe the receiving SMTP server will check the hostname that the sending SMTP server (in this case your server) and the connecting IP address, and the reverse dns lookup. So if you have your Domino SMTP server configured with hostname server.test.com (and that is what is sent in the HELO handshake of the SMTP protocol) and the IP address as seen by the SMTP server is *.212, then the *.212 NEEDS to reverse dns resolve back to server.test.com for it all to work.
I don’t think you need an A record for it, however for consistency it would be good to have.
Regards,
Mike Robinson
http://www.invcs.com
Subject: RE: AOL & Reverse DNS Issue? No Messages Outbound
Thanks… makes sense. I’ll see what happens and post response here. Have a great day.
Subject: AOL & Reverse DNS Issue? No Messages Outbound (Solved)
We added a PTR record for the server. Our IP address was incorrect the 1st time. Worsk 100% now. No matching A record is required. Use this link to verify that your reverse DNS lookup is 100% to AOL standards:
http://postmaster.aol.com/tools/rdns.html