change y
our port in smtp client configuration:-
SmtpClient client = new SmtpClient("smtp.gmail.com");
client.Credentials = new NetworkCredential ("myEmail@gmail.com", "myPassword");
client.Port = 587;
client.EnableSsl = true;
client.Send(mail);
to
SmtpClient client = new SmtpClient("smtp.gmail.com");
client.Credentials = new NetworkCredential ("myEmail@gmail.com", "myPassword");
client.Port = 465;
client.EnableSsl = true;
client.Send(mail);