C# 批量生成邮箱地址代码

private void button2_Click(object sender, EventArgs e)
        {
            string path = AppDomain.CurrentDomain.BaseDirectory + @"\" + "mail.txt";
            for (int i = 0; i < 50000; i++)
            {
                lock (lock_txt)
                {
                    File.AppendAllText(path, i + "@qq.com\r\n", Encoding.UTF8);
                }
            }
            MessageBox.Show("ok");
        }