XADM: How to Eliminate DNS’s MX records with Multiple Sites.

• Microsoft Exchange Server, version 4.0

SUMMARY

The MX record on DNS server is used to map a Fully Qualified Domain Name (FQDN) to a specific Microsoft Exchange Site or Host. This record can be eliminated if you do not want to use MX records on your DNS server. It can be done by changing the Microsoft Exchange Site Address to match the FQDN ("A" record) on your DNS server.

MORE INFORMATION

You can change this in the Microsoft Exchange Administrator program on the Site Addressing tab of the Site Addressing Property Page. When you are prompted to change the Mailbox address, reply yes so that all user SMTP e- mail addresses match the Site SMTP address. This must be done to all Microsoft Exchange Sites within the Organization.

The drawback to this type of configuration is that no two SMTP addresses can be the same within an Organization. Microsoft Exchange will keep this from happening on new mailbox creations if Directory Replication has happened between every Site in the Organization, and providing that no two instances of the Microsoft Exchange Administrator program are creating the same SMTP address at the same time.

For faster name resolution, it is common to have an MX defined, even if the A record is the same. This information is from the Microsoft Exchange Concepts and Planning Guide, page 46.