How to Verify that Your Outbound Port Is Set to Use Port 25
To configure the outbound port that your server uses to deliver Internet mail, use the Delivery tab in the SMTP virtual server properties. If you use the same gateway servers to send and receive Internet mail, the inbound and outbound ports should be set to port 25.
Before You Begin
Before you perform the procedure in this topic, read Connecting Exchange to the Internet.
The following permissions are required to perform this procedure:
- Member of the local administrators group and a member of a group that has had the Exchange View-Only Administrators role to view configuration, or the Exchange Administrators role to change configuration, applied at the administrative group level
Procedure
To verify that your outbound port is set to use port 25
Right-click Default SMTP Virtual Server, and then click Properties.
In Default SMTP Virtual Server Properties, click the Delivery tab. On the Delivery tab, you can specify outbound settings such as retry timers, outbound security and connection limits, and other advanced settings.
The Delivery tab in Default SMTP Virtual Server Properties
On the Delivery tab, click Outbound connections to set the TCP port that the server will use to connect to remote servers. The Outbound Connections dialog box appears.
The Outbound Connections dialog box
In Outbound Connections, verify that the TCP port is set to 25. Remote servers on the Internet expect your server to use TCP port 25. Changing TCP port to a value other than 25 is not recommended.