[CentOS] Force sendmail outbound routing for specific domain name

Thu Apr 10 03:21:02 UTC 2008
Hugh E Cruickshank <hugh at forsoft.com>

From: Frank Cox Sent: April 9, 2008 20:01
> On Wed, 09 Apr 2008 19:54:28 -0700
> Hugh E Cruickshank <hugh at forsoft.com> wrote:
> > Is it possible to force sendmail to use a specified host name for
> > outbound email to a selected domain name instead of the host name
> > that can be found by looking up the DNS entry?
> I'm not entirely sure that I understand your problem.  If you 
> have a unique
> domain name, and your client also has a unique domain name, and
> your dns
> records are properly configured, then sending email from domain 
> name A to domain
> name B should just work, regardless of how close your actual IP 
> addresses are.

I agree whole heartedly that it "should just work" but time and time
again we have see where it does not work.

> Having said that, you can put a domain name and IP address in 
> /etc/hosts on the
> originating computer and that computer will henceforth use the IP
> address
> specified there.

That would work if I was looking to use a specific IP address but
would like to use a specific host name. For example I would like
all mail outbound to example.com to bypass the DNS/MX entry of
mail.example.com and use instead backupmx.isp.com not just the IP
Address of backupmx.isp.com.

Thanks muchly for your suggestion.

Regards, Hugh

Hugh E Cruickshank, Forward Software, www.forward-software.com