To find the ports used by all your send connectors along with the smarthost used just open the shell and type:
Get-SendConnector | ft Id*,Sm*s,po*
Now, to send the port to something different just run Set-Sendconnector. So if the connector is called “OutboundMail” and you want it to use port 3535 it would be:
Set-SendConnector “OutboundMail” -port 3535