Setting up a IBM® Lotus® Domino® server as an SMTP server

SMTP Server

Setting up a IBM® Lotus® 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's 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 IBM® Lotus® 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

Configuring Domino to send mail to a relay host or firewall  

A relay host can be a server within your organization or an Internet Service Provider (ISP) that routes messages addressed to destinations outside the local Internet domain. Often the same server acts as a firewall through which your organization funnels all messages outbound to the Internet. It can be a IBM® Lotus® Domino® server or another type of server -- for example, a UNIX® sendmail server.
To configure internal SMTP servers to send mail to a relay host, you specify the IP address or host name of the relay host in the Configuration Settings document. If connections from the internal mail server to an ISP mail server pass through a firewall, specify the internal interface of the of the firewall in this field, and configure the firewall to forward traffic received on port 25 to the ISP mail server.
Servers that do not route mail over SMTP require special configuration to transfer messages to a relay host or firewall.
Configuring multiple relay hosts
To enable greater control over outbound message routing, you can configure multiple relay hosts. Using multiple relay hosts enables Domino to route mail addressed to certain Internet domains to certain relay hosts, without first performing a DNS lookup. For example, you can split external SMTP mail routing so that Domino routes all outbound Internet mail along one path, except mail addressed to a specific domain, such as *.acmepartner.com, which it sends through a specific SMTP server.
To configure multiple relay hosts, create a Foreign SMTP Domain document for each set of destinations, and then create SMTP connection documents to match these foreign SMTP domain documents. For example, using the previous example, you would create one Foreign SMTP Domain document for *.* and another for *acmepartner.com.
Foreign SMTP Domain documents are used by servers that route mail over SMTP as well as those using NRPC. For servers that use SMTP routing, Foreign SMTP Domain document indicate the destinations that need relay hosts and the relay hosts to use in each case.
To set up a relay host
  1. Make sure you already have a Configuration Settings document for the server(s) to be configured.
  2. From the Domino Administrator, click the Configuration tab and then expand the Messaging section.
  3. Choose Configurations.
  4. Select the Configuration Settings document and then click Edit Configuration.
  5. Click the Router/SMTP - Basics tab.
  6. Complete this field, and then click Save & Close:
Field Enter
Relay host for messages leaving the local Internet domain The host name, domain name, or IP address of the server being used as a relay host.
A domain name is a valid entry only if the internal DNS contains an MX record for that domain and can resolve it to a host name.
When entering an IP address, enclose it within square brackets; for example, [127.0.0.1].
  7. The change takes effect after the next Router configuration update. To put the new setting into effect immediately, reload the routing configuration.
  8. After you set up a relay host, you can set up restrictions based on where the message originated or the message destination.