By default OWA 2016/2019 ONPREMISE does not allow searching in the address book with the “department / service” field. OWA ONLINE allows you to do this.
If you want to activate this ONPREMISE feature, it is necessary to modify the Active Directory schema because OWA uses the fields available with an ANR (Ambiguous Name Resolution) criterion to search in the address book.
Warning: Modifying the Active Directory schema is a complex thing that must be evaluated in the context of a large volume. The impact of changing the ANR criterion can impact software such as provisioning software.
Modification of Active Directory schema
Activate the Active Directory schema administration tool with the command “regvr32 schmmgmt.dll”.
You can then add the “Active Directory Schema” tool to an MMC:
Activate the ANR option on the “Department” attribute:
Once the AD has been replicated, in OWA it will be possible to search by department in the enterprise address book: