Sendmail through DNS?

UNIX Solaris
1

Hello Guruz,

There is a mailserver with IPrange, i could able to resolve it through DNS,

nslookup <IP>
Its resolving.

But not pinging, port 25 is open for mailserver IP.

But when i am sending mail, i am geting the below error :frowning:

dsn=x.x.x, stat=Host unknown (Name server: xxx.xxx.xxx.xx: host not found)

Could some one tell me how to configure sendmail through DNS?

2

What is not pingable the mail server's name or the mail server's IP address?

Does an nslookup of the mail server's name resolves to its IP address correctly?

Here is a useful looking article on DNS and mail:
DynDNS.com - Support -- Knowledge Base -- E-mail, Mail Exchangers, and DNS
but it is more about mail routing which is an essential part of configuring mail.

3

Please post:

The correct name of the mail server and it's IP address.

Lines from sendmail.cf which mention the mail server by name and/or by IP address.
Lines from /etc/hosts which mention the mail server by name and/or by IP address.
The output from "nslookup" both by name and by IP address.
The contents of /etc/resolv.conf
The contents of /etc/nsswitch.conf

As TonyFullerManv deduced. Please post the output from the failing "ping" command.