Unoverica Message Transport v2.11 Chapter 5: Configuring Mail Routing

Chapter 5: Configuring Mail Routing

5.4 Scenario 3: Multi-Server Installations

Organizations with large networks will likely have many SMTP/POP3 mail servers installed across the companies networks. These networks typically use a single mail server for all incoming mail, while using the other mail servers for end-user delivery and POP3 access. Figure 5.31 below illustrates this type of network:

Figure 5.31: Networks with multiple SMTP/POP3 servers.

There are four steps that you must follow in order to implement this setup successfully:

Configure each of the Unoverica Message Transport mail servers in the network as described in section 5.2 Scenario 1: Routing Mail for a Domain. This will allow each system to accept mail for the local domain.
Configure the MX records for the domain so that they refer to the primary mail server. Optionally, you can configure the MX records so that they also point to the secondary mail servers as lower-priority backups. For more information on MX records and how they work, refer to section C.3.2.2 "MX" Records.
Enable the use of Unoverica Message Transport’s internal directory as described in section 4.2 Synchronizing NetWare Accounts with Unoverica Message Transport’s Directory.
Export the mail accounts from the secondary or departmental mail servers, edit the export files to change the user accounts to alias accounts, and then import the new alias accounts into the primary mail server’s directory. This procedure is documented in section 4.5 Exporting and Importing User Accounts.
You may also choose to configure the secondary mail servers so that they forward their out-bound mail to the primary mail server for distribution. Although this is not required for the architecture above to function, it may be required in order to meet security restrictions in force at your site. For information on how to achieve this, refer to section 5.3.1 Forwarding All Out-Bound Mail to a Relay Host.

Once these steps have been completed and the MX records have propagated throughout the Internet, then mail addressed to your domain name will be sent to the primary mail server, which will then expand the recipient’s e-mail address against the alias database, forwarding the mail to the correct mail server for the final recipient.

STEP: To learn more about Unoverica Message Transport’s advanced configuration options, go to Chapter 6: Advanced Configuration Options.