LinuxQuestions.org - Sendmail not working because of absence of DNS Server

- Linux - Networking (https://www.linuxquestions.org/questions/linux-networking-3/)

- - Sendmail not working because of absence of DNS Server (https://www.linuxquestions.org/questions/linux-networking-3/sendmail-not-working-because-of-absence-of-dns-server-702960/)

Sendmail not working because of absence of DNS Server

Folks,

I am trying to send a mail through sendmail to a remote machine.

"MSP" & "MTA" programs are running on both the local and the remote machine. Also I am being able to send the mail locally.

Sending mail on to remote machine is showing following message in "/var/log/maillog"

Quote:

Feb 7 22:45:49 station6 sendmail[7061]: n17Fx1en002609: to=<root@station5.cosec.com>, ctladdr=<root@station6.cosec.com> (0/0), delay=01:16:48, xdelay=00:00:00, mailer=esmtp, pri=390334, relay=station5.cosec.com., dsn=4.0.0, stat=Deferred: Name server: station5.cosec.com.: host name lookup failure

/etc/hosts file is properly configured and so as the /etc/nsswitch

My question to all:
Has anybody ever configured Sendmail to send the email remotely without configuring DNS?

Little Googly shows it can't be done:
http://linuxgazette.net/issue31/tag_maildns.html

I haven't test it but it may work if you want to send email to just one box.
You can define that box as a smarthost to your sendmail, so any non local mail will be forwarded to that smarthost. At smarthost the mail is local so it gets delivered to the mailboxes. Please note that the IP of the remote box should be enclosed in brackets:

Code:

DS[1.2.3.4]