MX record for internal AD domain to route outside?

Hi,
We have an Active Directory 2003 domain, with a local domain name of
xxxxxx.net (not domain.local). We also have an Exchange 2003 organization.
We make heavy use of our xxxxxx.net domain for internal e-mails.

Our execs have now decided to outsource our Exchange to a Host.

If I change the MX record for our internal domain on our internal DNS to
point to the external host's servers, will emails in our internal
xxxxxx.net be able to route correctly to our mailboxes on the Host's
servers?

Thanks for your help,
Max

You should never have messed with an MX record to start with. It was never
needed.

MX records are not for Clients to find their Mail Server.

MX records are for other "Unknown" Mail Servers out in Internet-Land to be
able to find your Mail Server to send inbound email to you. Those MX
Records should have been placed on the Public DNS Servers of whoever is the
Authoritcative DNS for your Public Domain. The fact that your Active
Directory FQDN happnes to be (or not be) spelled the same way as your Public
FQDN is irrelevant.

That has not changed. The only thing changed is that whoever is the
Authoritative DNS Sever for you Public FQDN has to alter their MX Record to
reflect the new IP for the Exchange as it is now hosted somewhere else.

You will now have to adjust all the companies email clients to point to the
new IP# of the Exchange server


--
Phillip Windell

The views expressed, are my own and not those of my employer, or Microsoft,
or anyone else associated with me, including my cats.
-----------------------------------------------------


"Max" <> wrote in message
news:...
> Hi,
> We have an Active Directory 2003 domain, with a local domain name of
> xxxxxx.net (not domain.local). We also have an Exchange 2003 organization.
> We make heavy use of our xxxxxx.net domain for internal e-mails.
>
> Our execs have now decided to outsource our Exchange to a Host.
>
> If I change the MX record for our internal domain on our internal DNS to
> point to the external host's servers, will emails in our internal
> xxxxxx.net be able to route correctly to our mailboxes on the Host's
> servers?
>
> Thanks for your help,
> Max

Thanks for the response Phillip. I'm sorry I didn't explain myself well
enough.

Many of our Linux servers send reports notifications and alerts to users
in the xxxxxx@net domain precisely because it is private, and not a
public DNS, so the MX record on our internal DNS is there for their
benefit - the linux servers are not in the domain. We wanted all the
mail to remain within our LAN, rather than being routed out to a public
SMTP server by a public MX, only to come right back to our mail server.

I just want to make sure that an ActiveDirectory integrated DNS holding
the xxxxxx.net zone which also has a live Exchange server, will
nonetheless accept an MX record that routes email for that same
xxxxxxx.net domain to outside the LAN to an external SMTP server.

Thanks again for your attention
Max

Phillip Windell wrote:
> You should never have messed with an MX record to start with. It was never
> needed.
>
> MX records are not for Clients to find their Mail Server.
>
> MX records are for other "Unknown" Mail Servers out in Internet-Land to be
> able to find your Mail Server to send inbound email to you. Those MX
> Records should have been placed on the Public DNS Servers of whoever is the
> Authoritcative DNS for your Public Domain. The fact that your Active
> Directory FQDN happnes to be (or not be) spelled the same way as your Public
> FQDN is irrelevant.
>
> That has not changed. The only thing changed is that whoever is the
> Authoritative DNS Sever for you Public FQDN has to alter their MX Record to
> reflect the new IP for the Exchange as it is now hosted somewhere else.
>
> You will now have to adjust all the companies email clients to point to the
> new IP# of the Exchange server
>
>

"Max" <> wrote in message
news:...
> Many of our Linux servers send reports notifications and alerts to users
> in the xxxxxx@net domain precisely because it is private, and not a public
> DNS, so the MX record on our internal DNS is there for their benefit - the
> linux servers are not in the domain. We wanted all the mail to remain
> within our LAN, rather than being routed out to a public SMTP server by a
> public MX, only to come right back to our mail server.

Ok, well that makes sense. Although the mail still remains in the LAN. The
path the message takes has nothing to do with the path the DNS Query against
the MX records goes. The DNS resolutiuon is already finished before the
mail even leaves,..and when it leaves it goes straight to the IP# that was
"discovered" by the resolution. The DNS resolution could go clear around
the planet but if the message destination is in the same physical room then
he message never leaves the room.

Another thing to consider is that the Apps on the Linux boxes may not even
have to use MX Records,...they would only do that if they have their own
private mail server built into the Application,...which is usually not the
case. The most common thing is that the Apps simply have an IP# in their
configuration for a chosen mail server that they use to relay the mail from.
So if you make you own mail server to be the one they use,...then the
message goes directly to the server they are supposed to go to and there is
no DNS resolution happening at all,..and that is the most efficient way to
do it.

> I just want to make sure that an ActiveDirectory integrated DNS holding
> the xxxxxx.net zone which also has a live Exchange server, will
> nonetheless accept an MX record that routes email for that same
> xxxxxxx.net domain to outside the LAN to an external SMTP server.

Now that statement does not make any sense at all. If you are outsourcing
your Exchange then you are not going to have one on your LAN,...or if you do
then thay cannot both operate with the same Mail Domain. Note I said Mail
Domain,...that is distinct from an Active Directory Domain or a Public
Domain,...although all three may often be spelled the same,...they are *not*
the same thing. You could have an Active Directory Domain called
"chickensoup.org",...have a Public Domain called "beefstew.com" and have a
Mail Domain called "@crunchycheese.net",...and it can all be the same
system. In reality it is only the Mail Domain that the Exchange is
concerned with and it is the Mail Domain that the MX record is concerned
with.

--
Phillip Windell

The views expressed, are my own and not those of my employer, or Microsoft,
or anyone else associated with me, including my cats.
-----------------------------------------------------