Routing internal mail

Internal mail consists of messages sent between users within an organization and its local Internet domains. The Domino® mail router (the Router) uses both SMTP and Notes® routing to transfer messages between network servers, and handles messages in both MIME format and Notes rich text format. By default, the Router transfers local mail using the Notes routing protocol only. Within a given Notes named network, servers that use Notes routing automatically transfer mail among themselves.

To use SMTP routing to transfer local mail, you must enable the SMTP listener for receiving mail and enable servers to send SMTP within the local Domino domain. In addition, the Server document for each SMTP-enabled server must specify a valid, fully qualified Internet host name for the server. In most cases the host name field is populated during server setup or by the Admin process (AdminP).

Implementing different protocols for internal and external routing

When selecting the protocol to use for internal mail routing, don't base your decision on whether you're using SMTP to transfer mail to external systems. Domino can send mail to the Internet even if you use Notes routing for internal mail. Rather than having all your servers route SMTP, you may want to retain a gateway-style architecture wherein you channel all mail to and from the Internet through a few designated servers and prohibit the majority of internal servers from sending directly to the Internet.

Ensuring support for Notes functionality

When choosing a routing protocol, consider security requirements and the need to support Notes applications. Using Notes as the internal routing protocol and SMTP for external routing can provide greater protection for your network against external intrusion. Certain Notes features, such as mail-enabled workflow applications, Notes public key security, and Notes items, such as Doc links, require Notes routing to work properly.

Routing mail to local users not listed in the Domino Directory

If you have users in your organization who are not listed in the Domino Directory, but in an alternate directory on another SMTP server, set up Domino to use this other server as a smart host. When processing a message in MAIL.BOX, if the Router comes across a recipient address that is in the local Internet domain, but does not have a match in the Domino Directory, it forwards the message to the specified smart host, which routes it to the recipient.

A Domino SMTP server in your organization may receive Internet mail for recipients in Domino domains that are within the local Internet domain, but outside the local Domino domain, and thus not listed in the Domino Directory. To ensure that the server can access other Domino Directories and route messages to servers in other Domino domains, configure Directory Assistance on the server.