public string AddEmails(string[] emails)
        {
            string errorMessage;

            _emailHelper.AddEmails(emails, out errorMessage);

            // Show a successful message if at least one e-mail is valid
            if (string.IsNullOrEmpty(errorMessage))
            {
                return("E-mails successfully added");
            }
            else
            {
                return(errorMessage);
            }
        }