Man lese auch:
https://docs.microsoft.com/en-us/exchange/email-addresses-and-address-books/address-book-policies/address-book-policies?view=exchserver-2019
ABPs won't function for Entourage and Outlook for Mac users who connect to their mailboxes from inside the corporate network, because Entourage and Outlook for Mac connect directly to a global catalog server to query Active Directory (which bypasses the ABPs). However, Entourage and Outlook for Mac clients that connect to their mailboxes from outside the corporate networks can use an OAB or Exchange Web Services (EWS), which allows them to search the GAL based on the assigned ABP. To learn more about administering Outlook for Mac 2011, see Planning for Outlook for Mac 2011.
betrifft also weniger die kundenzugriffe, sondern eure und das sollten dann eure Kunden wissen.