Enabling Reverse or NS Lookup

[jack102367]

I have been told that the reason we can't send emails to a certain company is because our server isn't set up for reverse or ns lookups.

Anyone know how to enable this?


Thanks,

Jack

 

[woonjas]

some mail servers check if there is a reverse dns entry for your server (some even check if it matches with the name your server uses) when it connects to the other mail server

check your DNS server records.

check what hostname your server is using when connecting, usually it's the internet hostname in the server document.

is your mail server using an public ip address or is it behind a NAT firewall?

lookup the ip address for your server's hostname and then do a reverse lookup for that server's ip address, this should have the same hostname as a result.

say my server document's hostname field contains: mail.acme.com

type on a w2k/nt4/xp commnand prompt: nslookup mail.acme.com
this wil give me an ip-address for example 212.136.23.12

then type in: nslookup 212.136.23.12 this should return the hostname mail.acme.com

hope this is helpful Woonjas
IRC: #notes on EFNet

 

[KoMAC]

Hello All,

It is related...
I've enabled Domino to check reverse NS of sender servers, but users complained, it refused a lot of custumers' mail... so I do not recommend to use this feathure.
Tamas

 

[Packet7]

Hello,
We recently had a problem sending email to AOL. It appears that AOL's new Spam filter will Quarantine your mail if a PTR record doesn't exist. We had PTR records configured at our ISP a while back, but somehow they got purged. The link below is very helpful with DNS issues. Good luck.

http://www.dnsstuff.com/

Rgds,

John Judge