I'm on an Android device (8.0) with the current Outlook Mobile. I'm unable to connect to my Exchange 2013 server as it throws a generic login failure. Oddly, I am able to connect fine with AndroidMail.
I did a
Get-MobileDevice -Mailbox me | fl FriendlName,Device*,Client*,Is*
and found that for unknown reasons it was blocked for Outlook Mobile on my current device ID (but allowed for devices I no longer have). I then did a
Set-CASMailbox -Identity:"me" -ActiveSyncAllowedDeviceIDs:"hexdeviceID"
My device now shows up as allowed with the Outlook Mobile string, but still will not function. Same exact login failure. I've reviewed the Exchange IIS logs and I see the pings. Everything appears to be successful (but I'm not skilled at reading Exchange logs). Anything in particular I should look for in Exchange?