Re: Maybe OT - Relaying question

[Dan Nelson]

In the last episode (Oct 02), Thomas Cameron said:
> I have a client with two mail servers - one that a big ISP manages
> and the one that will run SA 3.0.0 and spamass-milter-0.2.0+cvs-3. 
> My plan is to remove the ISP's mail server from the customer's DNS
> zone and send all mail to the SA + spamass-milter box, then have it
> relay to the ISP's mail server.
> 
> Question is, how to I tell sendmail to do this?  If DNS points to the
> SA + spamass-milter box, then how do I tell sendmail to forward the
> mail to the ISP's server?  Doesn't sendmail look to DNS to determine
> where to send its messages?
> 
> I am thinking I may need to set up a bogus DNS server on the SA +
> spamass-milter box to fake it into sending to the ISP's server.

You want to use the mailertable file.  It lets you force a next-hop
address for outgoing mail.  Something like this:

clientdomain.com        esmtp:bigisp.com

Will make sendmail forward emails addresses to clientdomain.com to
bigisp.com (using the standard MX lookup rules for the 'bigisp.com'
domain), no matter what the MX records for clientdomain.com are.  I use
a combination of mailertable and alias entries to funnel mail through
the email servers at work. More info at
http://www.sendmail.org/m4/mailertables.html .
 
-- 
        Dan Nelson
        address@hidden