SmtpClient client = new SmtpClient();
client.DeliveryMethod = SmtpDeliveryMethod.Network;
client.EnableSsl = true;
client.Host = "smtp.gmail.com";
client.Port = 587;
System.Net.NetworkCredential credentials =
new System.Net.NetworkCredential("your_account@gmail.com", "yourpassword");
client.UseDefaultCredentials = false;
client.Credentials = credentials;
MailMessage msg = new MailMessage();
msg.From = new MailAddress("your_account@gmail.com");
msg.To.Add(new MailAddress("destination_address@someserver.com"));
msg.Subject = "This is a test Email subject";
msg.IsBodyHtml = true;
client.Send(msg);