In this example, a single IBM® Lotus® Domino™ server, Mail2, handles messages from the Acme organization destined for other Internet domains (external addresses) and receives all mail addressed to the Acme Internet domain (acme.com). Mail2 has the field "SMTP used when sending messages outside of the local Internet domain" enabled on the Router/SMTP-Basics tab of the Configuration Settings document that applies to the server, and has the SMTP listener task enabled on the Basics tab of its Server document.

If a user on either of the two Acme internal mail servers, Mail1 or Mail3, sends a message to an external address -- one with a domain other than acme.com -- the server routes the message to Mail2, which can route mail to external domains. Any mail from an external Internet domain -- one other than acme.com -- is routed to Mail2, which is listed in the DNS as the Mail Exchanger (MX) host for acme.com. After the mail reaches Mail2, the server routes it to its destination.

The two internal mail servers, Mail1 and Mail3, can route Internet mail to the server with SMTP enabled for external mail (Mail2) either via IBM® Lotus® Notes® routing, with a Foreign SMTP Domain document and SMTP Connection document linking to Mail2, or via SMTP routing, with Mail2 configured as the relay host.

Configuring these servers requires:

• Enabling "SMTP used when sending messages outside of the local Internet domain" for Mail2.
• Enabling the SMTP listener task for Mail2.
• Setting up DNS correctly to list Mail2 as the connecting server for the acme.com domain for inbound mail.
• Either enabling "SMTP allowed outside of the local Internet domain" for Mail1 and Mail3 and listing Mail2 as the relay host, or creating a Foreign SMTP Domain document and SMTP Connection document that define the route to Mail2.

Sample mail routing configurations

Glossary