using relay to SMTP server

[tfreund]

I am running an application on a server with Red Hat Enterprise 2.1 and using sendmail as my MTA. The application sends e-mails as the application requires.

I have this application running on other similarly configured servers.

In this server though, a relay is used to reach the SMTP server. So, in sendmail.mc (and sendmail.cf) I have SMART HOST (DS in sendmail.cf) set to the URL (in this case an IP address) for the relay.

Problem is that no e-mails are getting through. I tried turning on the define for RELAY-ARGS and that makes no difference. I did a telnet to port 25 of the relay IP address and am getting through to the SMTP server OK.

Any suggestions to resolve this are welcomed

 

[elgrandeperro]

IP address for SMART_HOST? Most people put an entry in /etc/hosts, then refer to that entry.

Here is the awful example from sendmail doc:

SMART_HOST applies to names qualified with other hosts or bracketed addresses (e.g., "eric@mastodon.CS.Berkeley.EDU" or "eric@[127.0.0.1]").

The brackets usually disable the MX lookup (so perhaps [1.2.3.4] would work) but I would just do it the /etc/hosts way!

 

[tfreund]

I have tried surrounding the IP address with brackets. That failed. I then changed /etc/hosts to include the IP address for the relay and then placed the host name in the define for SMART_HOST. That did not work. One thing I noticed was that in /var/log/maillog, the entry for the sendmail of a test message had mailer=root@localhost (??). In another similar system where sendmail was working correctly, mailer was the host name set for SMART_HOST.

Any suggestions?

 

[elgrandeperro]

You rebuilding sendmail.mc or editting sendmail.cf? Are you stop/starting sendmail? That should also appear in the log file. Are the messages queued? What does mailq say?

 

[tfreund]

I recreated sendmail.cf via m4 on sendmail.mc. I will have to check on mailq. It sounds to me as if I have another reference missing to the relay, eventhough it's in /etc/hosts. But, I do not know where.

 

[elgrandeperro]

I assumed you stopped/started sendmail and installed the sendmail.cf in the correct place?

Always test with a new test message because it doesn't reprocess the queue with the new sendmail.cf.

Use "mailx -v MAIL_ADDRESS@mydomain.com" to see how it queues it and check the mail log and mailq to see how it fails.

If you don't see the relay host/ip in your log, I am assuming it is queued on your system.