ok fatto ma il problema non cambia al mio indirizzo con il quale ho un account su outlook arriva ad altri no. Posto il codice
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, ComCtrls, IdMessage, IdBaseComponent, IdComponent,
IdTCPConnection, IdTCPClient, IdMessageClient, IdSMTP;

type
TForm1 = class(TForm)
Button1: TButton;
IdSMTP: TIdSMTP;
IdMessage1: TIdMessage;
RichEdit1: TRichEdit;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
IdMessage1.Subject := 'Subject';
IdMessage1.From.Address := '.....@yahoo.it';
IdMessage1.Recipients.Add.Address := '......@yahoo.it';
IdMessage1.Body.Text :=richedit1.Text;
IdSmtp.Username := '.........';
IdSmtp.Password := '123456';
IdSmtp.AuthenticationType := atLogin;

IdSmtp.Host := 'smtp.mail.yahoo.it';
IdSmtp.MailAgent := 'Delphi';

IdSmtp.Connect(10);
try
IdSmtp.Send(IdMessage1);
except
on E: Exception do

begin

IdSmtp.Disconnect();
end;
end;
end;
end.

Grazie Alka scusami se ti faccio perdere tempo!