internal static IEnumerable <CultureInfo> GetDsnCultures(MailboxSession mailboxSession, HeaderList headerList, DsnHumanReadableWriter dsnWriter) { if (mailboxSession != null) { return(mailboxSession.InternalGetMailboxCultures()); } CultureInfo cultureInfo = null; if (headerList != null) { Header acceptLanguageHeader = null; Header contentLanguageHeader = headerList.FindFirst(HeaderId.ContentLanguage); cultureInfo = dsnWriter.GetDsnCulture(acceptLanguageHeader, contentLanguageHeader, true, null); } if (cultureInfo != null) { return(new CultureInfo[] { cultureInfo }); } return(Array <CultureInfo> .Empty); }