The outgoing port for an email account configured in Outlook 2016, 2013 and 2010 can be changed using the Change Account options. To change the outgoing port, click File menu then navigate to Account Settings and click the Account Settings dropdown arrow
This would display the following Account Settings window with different E-mail accounts.
Now select the e-mail account for which you want to change the port and then click the Change button. In the Change Account window, click the More Settings button to launch the Internet E-mail Settings window.
Navigate to Advanced tab and under the Server Port Numbers section, there will be option to specify the Outgoing server port.
After changing the port, click Ok button to confirm and save the changes.