Send mail using dot net

using System.Net;
using System.Net.Mail;

SmtpClient sp = new SmtpClient("smtp.gmail.com", 587);
//sp.Credentials = CredentialCache.DefaultNetworkCredentials;
sp.EnableSsl = true;
sp.Credentials = new NetworkCredential("madhusudan.gohil", "*************");
MailMessage m = new MailMessage("madhusudan.gohil@gmail.com", "ms_gohil@yahoo.com");
m.Attachments.Add(new Attachment(@"c:\amita.jpg"));
m.Subject = "test attach";
try
{

sp.Send(m);

}
catch (Exception ex)
{
Console.WriteLine(ex.StackTrace);
}