CONFIGURING
A smart host is a directory server to which SMTP-routed messages are sent when the message recipient cannot be found in the Domino® Directory or other secondary directories configured on the server.
About this task
Typically, a smart host is used in organizations that employ multiple mail systems within a single Internet domain. Users on these systems may not be in the Domino Directory. For example, if some users are on a UNIX™ sendmail system but their inbound messages are routed through the Domino mail system, you can set up a smart host to ensure proper address resolution.
After you set up a smart host, when Domino receives a message, if the domain part of the recipient's address matches the local Internet domain or one of the alternate Internet domain aliases defined in the Global Domain document, the Router looks up the address against all configured directories. If the address is not found, the Router then uses SMTP to forward the message to the configured smart host.
Domino sends all messages addressed to unknown recipients in the local Internet domain to the configured smart host. You cannot configure Domino to send to the smart host only messages addressed to recipients in some subset of the internal domains and domain aliases defined in the Global domain document. Domino does not send messages addressed to unknown Notes® addresses to the smart host.
You must have DNS set up correctly to use a smart host.
Procedure
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 these fields, and then save the document:
Note: If this field contains a host name entry and the field Verify that local domain recipients exist in the Domino Directory is enabled, messages addressed to local recipients that can not be resolved are not accepted; therefore, there is no transfer of messages to the smart host.
The change takes effect after the next Router configuration update. To put the new setting into effect immediately, reload the routing configuration.
Related concepts The Domain Name System (DNS) and SMTP mail routing Setting up how addresses are resolved on inbound and outbound mail Planning a mail routing topology
Related tasks Creating a Configuration Settings document Restricting users from receiving Internet mail Recalculating the server's routing table Setting up SMTP routing to external Internet domains Setting up SMTP routing within the local Internet domain Specifying how Domino looks up SMTP hosts when sending outbound mail