[thelist] Web and Email through different providors sharing a single domain

belinda at prodsol.net belinda at prodsol.net
Thu Aug 7 15:10:15 CDT 2003

It's possible - but it means that the host at the primary nameserver must set 
up custom host records for the mail.domain.com pointer.

For example:

I have primary DNS for all my sites on my Windows server (IIS).
Some of the webs are on the IIS machine, some are on a linux machine, and mail 
is ALL routed through one of my linux machines.

An example of the zone setup on the IIS DNS would be: (all made up IP numbers 

domain.com (Start of Authority): ns3.domain.com
Name Server: ns3.domain.com
Name Server: ns32.domain.com
domain.com (Host):
domain.com (MX): mail.domain.com
ftp.domain.com (Alias): domain.com
mail.domain.com (Host):
webmail.domain.com (Host):
www.domain.com (Alias): domain.com

Name servers at the registrar point to the Windows IIS machine.
Windows IIS machine has a Host record for domain.com that points to 
(a linux server)
mail.domain.com is set up as an additional HOST record in this zone, and points 
to yet another IP on another linux server.
webmail in the example above points to yet ANOTHER server.

For our purposes right now - this works well for a couple of reasons. 

1. I don't want to set up Exchange on my windows server, or a 3rd party mail 
server when I already have a linux server perfectly capable of handling all the 
mail for all my domains.

2. We are not a huge hosting company and deal with a relatively small amount of 
established client domains. (This setup requires manual manipulation of the DNS 
records in each zone. This would be CRAZY to do with hundreds or thousands of 

3. When moving sites between servers like I am in the process of doing now, 
because all my DNS entries are on one server I can simply change the host 
record IP when I move the site to its new location on a new box at a new host, 
and it takes less than an hour to reflect the DNS addressing change rather than 
72+ hours if I were changing the name servers at the registrar.

I would be interested in hearing opinions on the intelligence of this setup 
from those of you who are accomplishing the same thing in a different way, or 
if there are serious flaws in this setup that I should be considering. This 
configuration actually evolved into what it is now due to migration over the 
years between Cobalt Raqs, Windows, and other Linux builds.


Quoting hpinson at indepthl.com:

> What I am trying to avoid is passing (a lot of) company email through 
> ISP 1's web server, which has a mail server, but cannot handle a 
> large mail load.  Redirection via the Alias's would mean that the 
> mail still passes through, so is not a good option.

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