C# 实现发送qq邮件

public partial class Form1 : Form
    {

        public string smtpService = "smtp.qq.com";
        public string sendEmail = "*********@qq.com";//发送者
        public string receiveEmail = "*********@qq.com";//接收者
        public string sendpwd = "egzcyvcfexqlbfbd";//第三方登录码


        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {

            //确定smtp服务器地址 实例化一个Smtp客户端
            SmtpClient smtpClient = new SmtpClient();
            smtpClient.Host = smtpService;

            //smtpClient.Port = "";//qq邮箱可以不用端口
            //构建发件地址和收件地址
            MailAddress sendAddress = new MailAddress(sendEmail, "SP的我");

            MailAddress receiverAddress = new MailAddress(receiveEmail);//收件人

            //构造一个Email的Message对象 内容信息
            MailMessage message = new MailMessage(sendAddress, receiverAddress);
            message.Subject = "邮件主题" + DateTime.Now;
            message.SubjectEncoding = Encoding.UTF8;
            message.Body = textBox2.Text;
            message.BodyEncoding = Encoding.UTF8;
            //设置邮件的信息 如登陆密码 账号
            //邮件发送方式  通过网络发送到smtp服务器
            smtpClient.DeliveryMethod = SmtpDeliveryMethod.Network;
            //如果服务器支持安全连接，则将安全连接设为true
            smtpClient.EnableSsl = true;
            try
            {
                smtpClient.UseDefaultCredentials = false;
                //发件用户登陆信息
                NetworkCredential senderCredential = new NetworkCredential(sendEmail, sendpwd);
                smtpClient.Credentials = senderCredential;
                //发送邮件
                smtpClient.Send(message);
                MessageBox.Show("发送成功!");
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
    }