Downgrade from beta iOS

Remove the beta profile you have installed. Force it into recovery mode, and restore the currently shipping version of iOS using your computer.

You will NOT be able to restore a backup made with the iOS 16.1 beta to your phone running the shipping version of 16.0.2.

This is explained clearly in the documentation provided to you when you joined the beta program.

It is highly unlikely that the 16.1 beta is causing the Outlook mail error. You should troubleshoot the Outlook problem, not make a change that probably won’t fix it.