How to Mail mail From Gmail

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using System.Net.Mail; 



public void Send_Mail()
    {
        try
        {
            MailMessage mail = new MailMessage();
            mail.To.Add("vishal_verma54@yahoo.com");
            mail.From = new MailAddress("jeetu.choudhary13@gmail.com");
            mail.Subject = "test mail";
            mail.Body = "hi i am jeetu";
            SmtpClient smtp = new SmtpClient();
            smtp.Port = 587;
            smtp.EnableSsl = true;
            smtp.DeliveryMethod = SmtpDeliveryMethod.Network;
            smtp.UseDefaultCredentials = false;
            smtp.Host = "smtp.gmail.com";
            smtp.Credentials = new System.Net.NetworkCredential("jeetu.choudhary13@gmail.com", "*******");
            smtp.EnableSsl = true;
            smtp.Send(mail);
        }
        catch (Exception ex)
        {
            Response.Write("this is exception " + ex.Message);
        }
    }