SmtpClient使用介紹

備忘：需要引入兩個命名空間

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

程式部分：

private void button2_Click(object sender, EventArgs e)
        {
            Application.Exit();//退出程式
        }

        private void button3_Click(object sender, EventArgs e)
        {
            if (openFileDialog1.ShowDialog() == DialogResult.OK)
            {
                G_Attachment.Text = openFileDialog1.FileName;//擷取附件。
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string MyPsd = G_password.Text;
            string MyEmail = G_email.Text.Trim() + "@gmail.com";
            MailMessage MMsg = new MailMessage();
            MMsg.Subject = G_subject.Text.Trim();
            MMsg.From = new MailAddress(MyEmail);
            MMsg.To.Add(new MailAddress(G_address.Text.Trim()));
            MMsg.IsBodyHtml = true;//這裡啟用IsBodyHtml是為了支援內容中的Html。
            MMsg.BodyEncoding = Encoding.UTF8;//將本文的編碼形式設定為UTF8。
            MMsg.Body = G_content.Text;
            SmtpClient SClient = new SmtpClient();
            SClient.Host = "smtp.gmail.com";//google的smtp地址
            SClient.Port = 587;//google的smtp連接埠
            SClient.EnableSsl = true;//因為google使用了SSL（安全通訊端層）加密連結所以這裡的EnableSsl必須設定為true。
            SClient.Credentials = new NetworkCredential(MyEmail, MyPsd);
            if (G_Attachment.Text.Length>0)
            {
                MMsg.Attachments.Add(new Attachment(G_Attachment.Text));//判斷是否有附件
            }
            try
            {
                SClient.Send(MMsg);
                MessageBox.Show("郵件已經發送成功");
            }
            catch (Exception err)
            {

                MessageBox.Show(err.Message, "錯誤提示");
            }

         }

 執行個體2：

           string to = "get@tom.com";
           string from = "set@tom.com";
           MailMessage message = new MailMessage(from, to);
           message.Subject = "Using the new SMTP client測試郵件.";
           message.Body = @"測試郵件.";
           SmtpClient client = new SmtpClient("smtp.tom.com",25);
           // Credentials are necessary if the server requires the client
             // to authenticate before it will send e-mail on the client's behalf.
           client.Credentials = new NetworkCredential("set@tom.com","****");  //指定發送的使用者名稱，密碼
            client.Send(message);
            MessageBox.Show("發送成功ok");