Was trying to find a command to list what mailbox's have been accessed by the new Outlook app for iOS/Android. 

I am able to find out by single mailbox by using this command: Get-ActiveSyncDevice -Mailbox testuser | fl FriendlName,Device*,Client*,Is*

What I'm more interested in is one command that will tell me what mailbox's are accessing our Exchange environment using those apps. The reason is I'd like to see what kind of impact to the number of users this will affect when I quarantine to block access from this app to our Exchange environment. 

• Edited by bjp106 Monday, February 02, 2015 9:30 PM

I was able to adjust your command to get all the mailboxes in my environment.

Get-ActiveSyncDevice -Filter "*" | fl UserDisplayName,FriendlName,Device*,Client*,Is*

I feel like there's a better way to organize the output but this should get you the data you're looking for.

• Edited by ThmsRynr Monday, February 02, 2015 9:56 PM Added user display name to items shown in format-list.
• Marked as answer by bjp106 Tuesday, February 03, 2015 3:40 PM

Get-ActiveSyncDevice | Where {$_.DeviceOS -match "Outlook for iOS and Android 1.0*"}|out-gridview

For a more comprehensive report of your EAS devices this PowerShell script I wrote is pretty useful:

http://exchangeserverpro.com/powershell-script-activesync-device-report/