Sample Code to Test and Enable Mailbox programmatically C# (Dynamics 365/CRM)

      CrmServiceClient svc = new CrmServiceClient(ConnectionString);

            if (svc.IsReady)
            {
                var mailBox = new Entity("mailbox", new Guid("C88A539A-F493-EC11-B400-000D3A4F37D3"));

                // testemailconfigurationscheduled = Indicates if the email configuration test has been scheduled for a mailbox record
                mailBox.Attributes["testemailconfigurationscheduled"] = true;

                svc.Update(mailBox);