Good morning,

I have a couple of questions before I setup our OAuth for SDP Mail Settings.  We have a mix of users in our on-premise portal.  Most of our users are using AD credentials.  We also have external users that use Local Authentication accounts.  I started getting errors from our SDP about mail fetching errors this week and I'm setting up the OAuth today.  

1) Supported account types:  If I choose 'Accounts in this organizational directory only' will my Local authentication users still be able to login?

2) Our SDP portal is on premise and not available on the internet.  Will I also need to setup an Application Proxy?

3) I'm assuming I should use EWS for our Microsoft 365, but I currently have IMAP setup.  Does it matter which I choose?

4) Should I register SDP under Azure AD as an application or as an Enterprise Application?

Sorry, I know this is a lot.

Cathy S