Неверная кодировка текста в компонентах формы при получении почты через IdPOP3

AnsiString WinToKoi(const AnsiString St)
{
 char Win_KoiChars[] = {
      128,129,130,131,132,133,134,135,136,137,060,139,140,141,142,143,
      144,145,146,147,148,169,150,151,152,153,154,062,176,157,183,159,
      160,246,247,074,164,231,166,167,179,169,180,060,172,173,174,183,
      156,177,073,105,199,181,182,158,163,191,164,062,106,189,190,167,
      225,226,247,231,228,229,246,250,233,234,235,236,237,238,239,240,
      242,243,244,245,230,232,227,254,251,253,154,249,248,252,224,241,
      193,194,215,199,196,197,214,218,201,202,203,204,205,206,207,208,
      210,211,212,213,198,200,195,222,219,221,223,217,216,220,192,209};
 AnsiString Result=St;
 for (int i = 1; i <= St.Length(); i++)
 {
  if (int(St[i]) > 127)
    Result[i] = Win_KoiChars[St[i]];
 }
 return Result;
}
 
//---------------------------------------------------------------------------
AnsiString KoiToWin(const AnsiString St)
{
 char Koi_WinChars[] = {
      128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,
      144,145,146,147,148,149,150,151,152,153,218,155,176,157,183,159,
      160,161,162,184,186,165,166,191,168,169,170,171,172,173,174,175,
      156,177,178,168,170,181,182,175,184,185,186,187,188,189,190,185,
      254,224,225,246,228,229,244,227,245,232,233,234,235,236,237,238,
      239,255,240,241,242,243,230,226,252,251,231,248,253,249,247,250,
      222,192,193,214,196,197,212,195,213,200,201,202,203,204,205,206,
      207,223,208,209,210,211,198,194,220,219,199,216,221,217,215,218};
 AnsiString Result = St;
 for (int i = 1; i <= St.Length(); i++)
 {
  if (int(St[i]) > 127)
    Result[i] = Koi_WinChars[St[i]];
 }
 return Result;
}

void __fastcall TForm1::Button1Click(TObject *Sender)
{
TIdSMTP *IdSMTP = new TIdSMTP(NULL);
TIdMessage *Msg = new TIdMessage(IdSMTP);
  Msg->Subject = WinToWin1251Q(L"Тестовое письмо");  // WinToWin1251Q - самописная
  Msg->ContentTransferEncoding = L"base64";          // вот она, чудо строчка
 
  Msg->From->Name = WinToWin1251Q(L"Тестер");
  Msg->ContentType = L"text/plain; charset=windows-1251";
  Msg->Body->Add(L"Тело сообщения");
...
  IdSMTP->Connect();
  IdSMTP->Send(Msg);
  IdSMTP->Disconnect();
...
}
//---------------------------------------------------------------------------
UnicodeString __fastcall WinToWin1251Q(UnicodeString Str)
{
UnicodeString strTo;
  strTo.sprintf(L"=?windows-1251?Q?");
AnsiString sss = Str;
  for(int i=1; i<=sss.Length(); i++)
  {
byte a = sss[i];
    if (a == ' ') a = '_';
    strTo.cat_printf((a<128) ? L"%c" : L"=%.2X", a);
  }
  strTo.cat_printf(L"?=");
  return strTo;
}