Provide the API to get global address list from EMS service which should work on-premise as well as online Exchange (office 365)
Vern Weitzman commented
It's quite awkward to enumerate the GAL using EWS. When we use the Graph API, it is lacking basic attributes such as the HomePhone fields.
quyen pham commented
i think it is necessary,too
i am building an app for OWA but can not get information of email from EMS