string fromAddress, toAddress, msgSubject, msgBody;
fromAddress = "from@libero.it";
toAddress = "to@libero.it";
msgSubject = "prova";
msgBody = "hai letto";
SmtpClient client = new SmtpClient("smtp.libero.it");
MailAddress from = new MailAddress(fromAddress);
MailAddress to = new MailAddress(toAddress);
MailMessage message = new MailMessage(from , to);
//message.To.Add = toAddress;
message.Subject = msgSubject;
message.Body = msgBody;
client.Send(message);


cosi non vado in errore sull' add
ma al momento che la invio
mi da errore sull' invio