How to extract eMail adresses from a csv file

procedure readcsv(liste: string);
var
  i, b, at, lang, anfang, ende: Integer;
  email, csv: TStringList;
  found1, found2, atf: Boolean;
begin
  csv := TStringList.Create;

  csv.LoadFromFile(liste); // die angegeben csv auslesen
  email        := TStringList.Create;
  email.Sorted := True;
  found1       := False;
  found2       := False;
  atf          := False;

  for i := csv.Count - 1 downto 0 do
  begin
    for b := Length(csv.Strings[i]) downto 1 do
    begin
      if csv.Strings[i][b] = '@' then
      begin
        at  := b; //das @ suchen
        atf := True;
      end;
    end; //ende Buchstabe

    if atf = True then     //Wenn @ gefunden
    begin
      for b := at downto 1 do
      begin
        if found1 = False then
        begin
          if b = 1 then //Wenn Email am Anfang beginnt
          begin
            anfang := b;
            found1 := True; //anfang der E-Mail gefunden
          end;
          if csv.Strings[i][b] = ';' then   //Den ; vor dem @ suchen
          begin
            anfang := b + 1;
            found1 := True;  //anfang der E-Mail gefunden
          end;
        end;
      end; //ende suche begin
      found1 := False;


      for b := at to Length(csv.Strings[i]) do
      begin
        if csv.Strings[i][b] = ';' then
        begin
          if found2 = False then
          begin
            ende   := b;
            found2 := True; //Ende der E-Mail gefunden
          end;
        end;
      end; //ende suche begin
      found2 := False;
      lang   := ende - anfang; //Länge der Email-Adresse herausfinden
      email.Add(Copy(csv.Strings[i], anfang, lang)); //Die E-Mail zur Stringlist hinzufügen
      atf := False;
    end; //ende zeilen
  end; //ende ohne at
  Form1.ListBox1.Clear;
  Form1.listbox1.Items.addstrings(email);
  Form1.Label1.Caption := IntToStr(Form1.listbox1.Items.Count) + ' E-Mails gefunden!!';
  csv.Free;
  email.Free;
end; //ende readcsv


procedure TForm1.Button1Click(Sender: TObject);
begin
  readcsv('c:\test.csv'); //die Liste angeben
end;