How to get the GUID of mailboxes which has added under group.
Consider that i am having "TestGroup" mailbox group. Under this "mailbox1", mailbox2, mailbox3 are exist.
I am using ExpandGroup function to get members of group but the result is not having mailbox GUID.
How can i get GUID for those mailboxes using ews API ?
Why do you need the Mailbox Guid it won't be usable in EWS itself ? you can use the GetSearchableMailboxes https://learn.microsoft.com/en-us/exchange/client-developer/web-service-reference/getsearchablemailboxes-operation which is the only operation that will return the GUID in EWS in know of. If you using Office365 using then you can get this information using the Graph API much easier.
