Upcoming Exchange Online Device Access and Conditional Access changes with Outlook mobile

Martijn Tigchelaar Let me clear up some misconceptions.

1. Outlook mobile does not utilize the Exchange ActiveSync protocol. It uses the Microsoft sync technology (https://docs.microsoft.com/exchange/clients-and-mobile-in-exchange-online/outlook-for-ios-and-android/outlook-for-ios-and-android). The change in this article is specific to Outlook mobile and does not affect mobile clients utilizing the ActiveSync protocol.
2. With the change highlighted in this article, if an Outlook mobile was previously allowed to connect by an incorrect Conditional Access policy, with this change, that same Outlook mobile client would be blocked by the Exchange Online mobile device access policy (if set to quarantine/block) and that device ID was not already defined in the user's ActiveSyncAllowedDeviceIDs.
3. The reason that Outlook mobile utilizes a virtual device ID is because apps are prevented by the OS platform from accessing certain physical device parameters that would make obvious ID choices. As a result, the app has to generate its own device ID. For example, since iOS7, certain hardware information is restricted from third-party apps (e.g., https://code.i-harness.com/en/q/2f29e and https://forums.developer.apple.com/thread/7560).