The_Exchange_Team Thanks for clarifying this plan. We hope that all our devices and apps using SMTP AUTH today will add support OAuth with SMTP AUTH.
However, we do see many old devices and apps that probably never get support for anything else than just SMTP AUTH. Is the plan long term (1-5 years?) to completely turn off SMTP AUTH for all mailboxes (even our exceptions)? Just trying to check if we need to start planning to spinning up our own on-premises SMTP gatways on our local network for these old legacy devices and apps.