public static string ToMimeFormat(this MessageFlags flags)
        {
            var result = string.Empty;
            var text   = flags.ToString();
            var items  = text.Split(Characters.Comma);

            result = items.Select(item => item.Trim()).Aggregate(result, (current, trimmed) => current + (@"\" + trimmed + Characters.Space));
            return(result.Trim());
        }