App Protection Policies and Shared/Delegate Mailboxes with Outlook mobile

Hi Ross Smith IV,

I really like your article.

We have a lot of users having multiple accounts in the same domain (please don't ask why). Using app protection policies we want to prevent sending corporate data using personal applications (like WhatsApp). Adding the account like a delegated mailbox works like a charm on the mobile devices, however the user can still add his additional account using "add account" in the Outlook app. Then the additional account is not protected by app protection policies. Can we prevent users from adding more then one account in the Outlook app somehow? we only use app protection policies and not full device management because some of the devices are personal devices.

Any idea if Microsoft is working on a solution for this?