Exchange 2003 Complex issue

[robertscl]

I am building a windows 2003 server Domain and using exchange 2003 for mail servers.

Description of Network:

1 Forest 1 Domain (I do not want to use sub-domains)
6 Sites
1 Domain Controller and 1 Exchange server at each site
DNS running on each DC (DNS are running as Secondary DNS)
Active Directory is organized in accordance with the specific sites.

Goal:

My goal and intentions is to have each site opperate on its own if the WAN connections go down. Each DC is setup as a cached global catolog. The main purpose is to minimize traffice betwen sites and to make all network resources from loging in to email available on the LAN if the WAN drops. All users mailboxes with in a specific site will reside on that sites exchange box.

Problem at hand:

The problem that I am running in to is how properly route the email traffic with exchange and DNS. The MX record will be on the primary DNS so if there link goes down how will the traffic be routed and how can keep exchange still functioning properly so that email with in the local site will still function.

[DShack]

If you are really only concerned about whether your primary site goes offline, choose one other site to be the backup site, set up another MX record with a higher priority for that site, and make sure that that site can communicate and route mail to the rest of the sites. That way if your primary is down, your secondary will recieve the mail and route it appropriately to whichever site is the proper destination.

If you want full redundancy, you would configure ALL your sites for inbound mail and configure an MX record that points to each site, so that there will always be at least one site available to receive and route mail.