private static void CheckHtml(MimeEntity entity) { if (entity.DataText.Trim().Length == 0) { entity.WrapDataText("<html>", "</html>"); } else { var ipos = 0; var c = entity.DataText[ipos]; while (ipos < entity.DataText.Length - 1 && (c == ' ' || c == '\t' || c == '\r' || c == '\n')) { c = entity.DataText[++ipos]; } var dtstr = entity.DataText.Substring(0, "<!DOCTYPE".Length); if (dtstr.ToUpper() == "<!DOCTYPE") { ipos = entity.DataText.IndexOf('>', ipos + "<!DOCTYPE".Length); while (ipos < entity.DataText.Length - 1 && (c == ' ' || c == '\t' || c == '\r' || c == '\n')) { c = entity.DataText[++ipos]; } } if (ipos > 4 && ipos < entity.DataText.Length - 5) { var hdr = entity.DataText.Substring(ipos, 4); if (hdr.ToLower() == "<div") { entity.WrapDataText("<html>", "</html>"); } } else { entity.WrapDataText("<html>", "</html>"); } } }