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Changing outbound SMTP port settings
Outbound SMTP port settings affect how IBM® Lotus® Domino® connects to other SMTP servers. Change the default port numbers and the status of the TCP/IP and SSL ports to match the settings on servers to which this server sends SMTP mail.

The outbound port settings apply to all outbound SMTP sessions. If you change an outbound port number to a nonstandard value, the server cannot establish SMTP connections with servers that listen for SMTP requests on the standard port. Similarly, if you set up the server to send SMTP over SSL only, disabling the outbound SMTP TCP/IP port, the server cannot establish SMTP connections with a remote server that accepts SMTP connections over the TCP/IP port only.

To change outbound SMTP port settings

1. From the Domino Administrator, click the Configuration tab and then open the Server document for the server that runs the SMTP service.

2. Click the Ports - Internet Ports - Mail tab.

3. In the Mail (SMTP Outbound) column, complete these fields, and then click Save & Close:
FieldEnter
TCP/IP port numberThe number of the TCP/IP port on the remote server to which Domino attempts to connect when initiating an SMTP session. The default and industry standard port for SMTP connections over TCP/IP is 25. Specify a nonstandard port only if this Domino server makes all of its outbound SMTP connections over TCP/IP to a server that uses the nonstandard port.
TCP/IP port statusChoose one:
  • Enabled - The Domino SMTP Router connects to the designated TCP/IP port number on a remote server to initiate an SMTP session. If the SSL port status is also set to Enabled, the Router attempts to use the SSL port first and uses the TCP/IP port only if it cannot connect to the SSL port.
  • Disabled (default) - The Domino SMTP Router cannot initiate an SMTP session using the TCP/IP port on a remote server.
  • Negotiated SSL - The Domino SMTP Router connects to the designated TCP/IP port on a remote server to initiate an SMTP session. If the remote server advertises STARTTLS during the EHLO greeting, Domino issues a STARTTLS command to request that the remainder of the session be encrypted using SSL. If the remote server does not support STARTTLS, an unencrypted TCP/IP session ensues.
SSL port numberThe number of the SSL port on the remote server to which Domino attempts to connect when initiating an SMTP session. The default and industry standard port for SMTP connections over SSL is 465. Specify a nonstandard port only if this Domino server makes all of its outbound SMTP connections over SSL to a server that uses the nonstandard port.
SSL port statusChoose one:
  • Enabled - The Domino SMTP Router connects to the designated SSL port number on a remote server to initiate an SMTP session. If the Router cannot connect to the SSL port and the TCP/IP port is also enabled on both the Domino server and the remote server, Domino makes a second attempt to connect, using the designated TCP/IP port.
  • Disabled (default) - The Domino SMTP Router cannot initiate SMTP sessions over the SSL port of a remote server.
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