[CentOS] sendmail not sending after reboot

Les Mikesell lesmikesell at gmail.com
Tue Jun 10 12:49:09 UTC 2008

Kai Schaetzl wrote:
>> I made that change 
>> you suggested in the webmin interface (sendmail.m4) and rebuilt it from 
>> there.
> You can m4 rebuild the sendmail.cf from the sendmail section in webmin? I 
> wouldn't be to sure about that. I haven't ever noticed that might be 
> possible (I use webmin only to manage the various sendmail databases, not 
> the configuration). Do you have sendmail-devel installed?

A 'make' is run when the sendmail init script starts that will rebuild 
sendmail.cf from sendmail.mc if it is newer, and all the databases if 
their corresponding text file is newer.

> Removing the localhost from daemon options won't change anything. It was 
> working before, just with a timeout (which means the settings from this 
> file were not in use!), so sendmail *is* listening on all interfaces 
> already.

A reboot would trigger the rebuild from sendmail.mc.  Perhaps it was 
changed after sendmail was working before.  Backups of the files in /etc 
are always a good thing...

> Now, by recompiling the sendmail.cf from m4/mc files (if that  
> really was done) that you may have never used before you might have 
> introduced more problems.
> If your sendmail.cf did not change a tiny bit from before the working 
> state then the problem is *not* in sendmail.cf, but somewhere else. And 
> Stephen's hints to DNS and the connection to rebooting make sense to me. 
> Anyway, it cannot be sendmail.cf unless you changed it and didn't restart 
> it after the change. (If you made all changes with webmin then it got 
> restarted each time.)

You should be able to tell by the timestamps, but you can easily tell if 
sendmail is listening by trying to telnet to port 25 from another 
machine.  If it accepts connections, you should be able to diagnose 
other problems from the /var/log/maillog entries.  If it doesn't, check 
the daemon options and any firewalling you might have.

   Les Mikesell
    lesmikesell at gmail.com

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