SMTP Send Connector Port
By default the SMTP Send Connector is set to use port 25 with a Smart Host. However if you need to change the port from port 25 to port 587 or any other port, then follow the below instructions.
Launch the Exchange Management Shell (EMS). (Otherwise known as Exchange Power Shell) It’s in Start>All Programs>Microsoft Exchange Server 20xx>Exchange Management Shell
Use the following command in the Exchange Management Shell to get the current Connector information.
Windows SBS Internet Send “Your SBS server name” will be the connector name in SBS installations. You must type the command exactly like you see it with spaces and capitalization.
To change the port to 587 use the following command
Set-SendConnector “Your SMTP Send Connector” -Port 587
Notice: The commands are case sensitive. You must type them EXACTLY as you see them. The send connector name must be inside quotes..”send connector name” .
Reboot the server and send a test mail. Then check the outgoing queue. Poof. That’s it!
Note: The last time I had to make this change, I was forced to use my SMTP servers IP address instead of the server name, even though it resolved ok. If you aren’t successful, try using your SMTP servers IP address instead of the SMTP server name. I have no idea why it makes a difference.