protected List <MailUserFolderData> GetUserFolders()
        {
            if (UserFolders == null)
            {
                UserFolders = new List <MailUserFolderData>();
            }

            if (UserFolders.Any())
            {
                return(UserFolders);
            }

            UserFolders = EngineFactory.UserFolderEngine.GetList();

            return(UserFolders);
        }