OAuth is more indirect and annoying, but they even tell you how to do it with your own client: https://learn.microsoft.com/en-us/exchange/client-developer/lega

OAuth is more indirect and annoying, but they even tell you how to do it with your own client: https://learn.microsoft.com/en-us/exchange/client-developer/legacy-protocols/how-to-authenticate-an-imap-pop-smtp-application-by-using-oauth https://learn.microsoft.com/en-us/exchange/client-developer/...