How to block ActiveSync for Office 365 users in Exchange Online

Navigate to the Exchange Control Panel

Browse To the Exchange Control Panel: http://outlook.office.com/ecp

Select mailboxes and locate the desired mailbox.

Select the desired mailbox via search.

Under mailbox features -> Disable, select Exchange ActiveSync

Under mailbox features -> under phone and Voice Features -> Disable ActiveSync, choose.

Query mobile devices through AciveSync?

The View details option (as shown in the image above) allows you to view all currently connected devices.

Login at PowerShell in Exchange Online

Using these instructions, connect to Exchange Online with PowerShell.

Block ActiveSync through Microsoft PowerShell

Set-CASMailbox -Identity <Mailbox ID> -ActiveSyncEnabled $False

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