Exception to Client Access Rule is not working

Question

Hello,

One more question, please: I've added the new client access rule with the following parameter:

-ExceptUsernameMatchesAnyOfPatterns ****.net\A_Oliver

...but Exchange still keeps applying this rule to *******.net\A_Oliver

???

Thank you in advance,
Michael

Answer 1

@Mikhail Firsov
From the title of EMS, I guess you are using Exchange on-premises rather than Exchange Online.

About "-ExceptUsernameMatchesAnyOfPatterns", it available only in Exchange online:

You may could use this attribute in Exchange on-premises, but it won't do anything.

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Answer 2

Hi,

Try using UserRecipientFilter instead of ExceptUsernameMatchesAnyOfPatterns.

Set the CustomAttribute1 to Test for the user who needs to be added as an exception. In this case for A_Oliver.

Create a new clientaccess rule like below,

New-ClientAccessRule -Name "Block EAC Access” -Action DenyAccess -UserRecipientFilter {CustomAttribute1 -ne “Test”} -Priority 2

Then test it using the Test-ClientAccessRule

https://www.codetwo.com/admins-blog/how-to-block-external-access-to-exchange-admin-center-in-exchange-2019-via-client-access-rules/

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Answer 3

Thank you all for your replies!

Sorry, missed it ("Applies to: Exchange online"). Thank you, AshokM-8240, for another method (Client-AccessRule).

Regards,
Michael