使用 SmtpClient 时“操作超时”

Question

I am trying to create a small app using C# framework to send email. However, it does not work. The app always gives me "The operations timed out." I do not why.

Here is my code:

private void button1_Click(object sender, EventArgs e)
   {
     MailAddress fromAddress = new MailAddress("from@gmail.com");
     MailAddress toAddress = new MailAddress("to@gmail.com");

     MailMessage mail = new MailMessage(fromAddress.Address, toAddress.Address);
     mail.Subject = "Testing";
     mail.Body = "contents.";

     SmtpClient client = new SmtpClient();
     client.Host = "smtp.gmail.com";
     client.Port = 587;
     client.EnableSsl = true;
     client.Timeout = 100;
     client.UseDefaultCredentials = false;
     client.Credentials = new NetworkCredential("username", "password");

     try
        {
            client.Send(mail);
            MessageBox.Show("Mail Sent!", "Success", MessageBoxButtons.OK);
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK);
        }

    }

Thanks!

Answer 1

Try to set a higher timeout limit. It is in milliseconds.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Net.Mail;
using System.Net;

namespace GmailSendTest
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            MailAddress fromAddress = new MailAddress("myusername@gmail.com");
            MailAddress toAddress = new MailAddress("myusername@gmail.com");

            MailMessage mail = new MailMessage(fromAddress.Address, toAddress.Address);
            mail.Subject = "Testing";
            mail.Body = "contents.";

            SmtpClient client = new SmtpClient();
            client.Host = "smtp.gmail.com";
            client.Port = 587;
            client.EnableSsl = true;
            client.Timeout = 10000;
            client.UseDefaultCredentials = false;
            client.Credentials = new NetworkCredential("myusername", "mypassword"); 

            try
            {
                client.Send(mail);
                MessageBox.Show("Mail Sent!", "Success", MessageBoxButtons.OK);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK);
            }
        }
    }
}