I am using it as smtp.gmail.com for sending mails.
code look like:
MailMessage mm = new MailMessage();
mm.From = new MailAddress("yourmail@gmail.com", "sharepoint");
mm.To.Add(new MailAddress("mail@gmail.com"));
mm.subject="subject";
mm.Body = "Body";
SmtpClient sc = new SmtpClient("smtp.gmail.com");
sc.Credentials = new System.Net.NetworkCredential("yourmail@gmail.com", "yourpassword");
sc.EnableSsl = true;
sc.Send(mm);