Configuring Domino to send and receive mail over SMTP

Setting up an IBM® Domino® server as an SMTP server consists of enabling two separate tasks: a listener task and a routing task. Enabling the SMTP Listener allows a server to receive mail over SMTP. Enabling SMTP routing lets the Domino Router send mail to other servers using SMTP.

You enable SMTP routing to destinations within the local Internet domain separately from SMTP routing to external destinations. It is also possible to enable SMTP routing on a server without enabling the Listener task, and vice-versa.

For example, to support POP3 and IMAP clients, which use SMTP to send mail, you must have at least one internal server running the SMTP Listener task. However, the server does not have to use SMTP when transferring messages it receives over SMTP to the next hop on the routing path. After the server has accepted a message over SMTP, it can use Notes® routing to transfer the message to other servers.

By default, Domino uses Notes routing only and is not configured for SMTP routing. To have Domino use SMTP to send and receive mail, do the following:

Prepare your system for sending messages to the Internet by testing your Internet connection and verifying that DNS is set up properly.
Enable the SMTP Listener task in the Server document of each server you want to receive mail over SMTP
Enable SMTP routing within the local Internet domain so that servers can send mail over SMTP within the local Internet domain.
Enable SMTP to be used to send messages outside the local Internet domain.
Specify the relay host, if any, to be used when sending mail outside the local Internet domain. Configure a relay host for SMTP servers that do not have direct access to the Internet.
Set up inbound and outbound mail restrictions to protect against misuse of the mail infrastructure.
To allow POP3 or IMAP users who connect to Domino from an external network to send mail to external Internet domains, specify exceptions to inbound relay enforcement for authenticated users.

If you intend to allow users to access mail from POP3 or IMAP mail clients, you must install and enable these access protocols on users' mail servers. By default, Domino supports only Notes client access.