public static MailboxSession CreateMailboxSessionForConfiguration(ExchangePrincipal groupPrincipal, string domainController)
        {
            MailboxSession mailboxSession = MailboxSession.OpenAsAdmin(groupPrincipal, CultureInfo.InvariantCulture, "Client=WebServices;Action=ConfigureGroupMailbox");

            mailboxSession.SetADRecipientSessionFactory((bool isReadonly, ConsistencyMode consistencyMode) => DirectorySessionFactory.Default.GetTenantOrRootOrgRecipientSession(domainController, isReadonly, consistencyMode, null, groupPrincipal.MailboxInfo.OrganizationId.ToADSessionSettings(), 127, "CreateMailboxSessionForConfiguration", "f:\\15.00.1497\\sources\\dev\\UnifiedGroups\\src\\UnifiedGroups\\GroupMailboxAccessLayer\\Commands\\ConfigureGroupMailbox.cs"));
            return(mailboxSession);
        }