[CentOS] one server handled sendmail added two more servers messes things up

[Les Mikesell]

Jerry Geis wrote:
> Hi all,
> 
> I had one server running centos 4.7 i686  everything was fine with 
> incoming mail.
> 
> I now added two more servers centos 5.4 x86_64 and gave them machine 
> names all
> part of the same domain as machine 1. I noticed that incoming emails are 
> being
> round robined to all three machines.  At this time I really just want 
> the one original machine
> to handle my incoming email... The other two new machines are for other 
> purposes.
> 
> How do I tell the two new machines that all incoming email send to 
> machine 1.
> Is there an easy way to do that? At this point I just turned off the two 
> new machines
> and all mail is coming into the original machine just like before.

This should be controlled by the DNS MX record for the domain name.  Just set it 
to the machine(s) you want to receive mail.  If you want more than one to 
receive mail but forward it all to one for delivery, set MAIL_HUB in the 
sendmail.mc file on the ones that should forward (usually that's not necessary, 
though).