In Exchange you can hide a Mailbox from the (Global) Address List. But after you have hidden a Mailbox you cannot create an Outlook profile for it (or add it as an extra mailbox).
When you click "Check Name" you receive error: The action cannot be completed. The name could not be matched to a name in the address list.
The common workaround is to remove the “Hide from Exchange address lists” setting, create the profile (or add the Mailbox) and afterwards set it again.
Once the profile is created it all keeps working.
There is an easier solution though!
Using PowerShell execute very simple script:
Add-Type-AssemblyName System.DirectoryServices.AccountManagement$ct=[System.DirectoryServices.AccountManagement.ContextType]::Domain$user=[System.DirectoryServices.AccountManagement.UserPrincipal]::FindByIdentity($ct,"MYDOMAIN\gtest01")$user.GetUnderlyingObject().legacyExchangeDNSave the script to scriptname.ps1 and execute from PowerShell.
The result of the script you can use au a user name to check.
TIP:
1. And two last lines of code to extract multiple users.
2. To save result into file, run: ./scriptname.ps1 > file.txt