[Descendents]

Ya lo he conseguido lo pongo aqui lo que me ha ayudado por si alguien le sirve

Código Delphi [-]
var
  idAttach: TidAttachment;
  idText1: TidText;
  idText2: TidText;
  p: TidMessageParts;
  slBody: TStringList;
begin
  idMessage1.Recipients.Add;
  idMessage1.Recipients[0].Address := 'girlswants_me@yahoo.com';
  p := idMessage1.MessageParts;
  slBody := TstringList.Create;
  try
    // you can actually load the body from a RichEdit with 
    // slBody.Text := RichEdit1.LinesText;
    slBody.Add('');
    slBody.Add('');
    slBody.Add('');
    slBody.Add('');
    slBody.Add('

Here is the image:


');
    slBody.Add('');
    slBody.Add('');
    slBody.Add('');
    idText1 := TidText.Create(p, slBody);
    idText1.ContentType := 'text/html';
    idText2 := TidText.Create(p);
    idText2.ContentType := 'text/plain';
    idText2.Body.Text := '';
    // This shows how to add an attachment
    idAttach := TidAttachment.Create(p, 'c:\sm101yellow.jpg');
    idAttach.ContentType := 'image/jpeg';
    idAttach.ContentDisposition := 'inline';
    idAttach.ExtraHeaders.Values['content-id'] := 'sm101yellow.jpg';
    idMessage1.Body.Assign(slBody);
    idAttach.DisplayName := 'sm101yellow.jpg';
    idMessage1.ContentType := 'multipart/mixed';
    idSMTP1.Connect;
    idSMTP1.Send(idMessage1);
  finally
    idSMTP1.Disconnect;
    slBody.Free;
    Showmessage('done');
  end;
end;

//Lo modifique para colocar las etiquetas Delphi

Un saludo
Gracias