Restricting EWS Access - Problem on Exchange 2010 SP2

Hi,

Using Exchange 2010 SP2 I want to restrict EWS Access - so a specific user can only use EWS if he sends the correct user-agent.

I did it this way using PS:

Set-CASMailbox -Identity 'useraccountname' –EWSApplicationAccessPolicy: EnforceAllowList –EWSAllowList: {“the useragent string of the app”}

Unfortunately this does not work, I still am able use EWS with this account with any user-agent

Even disabling EWS all-together for this user does not work (just for testing):

Set-CASMailbox -Identity 'useraccountname' –EWSEnabled $False

I can still access EWS with EWSEditor for example.

Attached are screenshots of Get-CASMailbox and a screenshot of EWSEditor accessing EWS without a problem although EWSEnabled is set to False for the User.

Edit: For testing I also set OWAEnabled to $False and the user was instantaneously unable to acces OWA.

Any help would be greatly appreciated!

Thanks!
Philipp

Get-CASMailbox (EwsEnabled = False, so no EWS Access should be permitted)

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Logged in with this user using EWSEditor (I am impersonating another user, but I am logging in as the user that should not be able to log in):

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