split dns, MX records, and sending mail from a Win2K server

vze78se7 at verizon.net vze78se7 at verizon.net
Thu Oct 21 20:55:22 UTC 2004

Hi: I'm a little confused about split DNS.

I have a webserver (Win2K), DNS (Linux/BIND 9.2.3)  and a separate
mailserver on a 192.168.1.x subnet.

I've set up a "local.domain.com" zone and added it to my named.conf
file under the local view for that subnet.

I have the primary DNS for the webserver (Win2K server) as the BIND
server. If I perform an nslookup from the webserver, it correctly
returns the local IP addresses for various servers specified in the
"local" zone file.

Here's the problem. I send out emails from the webserver using CDO. If
I have a customer service form, when constructing an email I specify
the recipient to be something like "service at mydomain.com", where
"mydomain.com" is the site being hosted on the webserver.

When CDO drops the email in the outgoing mail folder, it never gets
delivered. The event log says something like:

"Message delivery to the remote domain 'mydomain.com' failed for the
following reason: The connection was dropped by the remote host."

My local.mydomain.com zone file looks like:

	IN NS ns.myhostsdomain.com

	IN MX 10	mail

	IN A	//the webserver
mail	IN A	//the mailserver
www	IN A	//the webserver

But I think what's happening is mail addressed to "mydomain.com" is
never being sent to the mailserver...like the MX record's being
ignored and it's trying to send mail back to itself.

I ended up getting things to work by adding an entry in the hosts file
on the webserver like:	mydomain.com	#the IP of the mailserver

but the only reason this works, I believe, is because the hosts file
is queried before the NS.

I guess this is really a Win2K question, but I'm hoping someone may
have been through this before and can explain where I'm going wrong.


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