The server port for SMTP (default 25).
This property contains the server port for SMTP (default 25). A valid port number (a value between 1 and 65535) is required for the connection to take place. The property must be set before a connection is attempted and cannot be changed once a connection is established. Any attempt to change this property while connected will fail with an error.
For implicit SSL, use port 465 (please refer to the SSLStartMode property for more information).
This property is not available at design time.