用Mail Server幫你寄信
using System.Net.Mail
using System.Net
該程式利用 MailAddress 建立收發信人的郵件位址，MailMessage 建立郵件相關內容，SmtpClient 與 NetworkCredential 建立 Smtp 連線認證與寄信功能。
public void SendMail()
{string fromEmail = "XXX@gmail.com";//來源信箱
string fromName = "C.H.Huang";//寄件者
MailAddress from = new MailAddress(fromEmail, fromName, Encoding.UTF8);
string toEmail = "ddmcmail02@ddmc.feg.com.tw";//目的信箱
MailMessage mail = new MailMessage(from, new MailAddress(toEmail));
string subject = "信件標題";
mail.Subject = subject;
mail.SubjectEncoding = Encoding.UTF8;//信件標題編碼方式
string body = "<html>test</html>";//信件內容
mail.Body = body;
mail.BodyEncoding = Encoding.UTF8;//信件內容編碼方式
mail.IsBodyHtml = true;//信件內容html編碼
mail.Priority = MailPriority.High;
// SMTP Setting
SmtpClient client = new SmtpClient();
client.Host = "smtp.gmail.com";//Mail Server主機
client.Port = 587;//開放寄信的port
client.Credentials = new NetworkCredential("username@gmail.com", "password");//寄信者帳號,密碼
client.EnableSsl = true;//是否有安全性加密
// Send Mail
client.Send(mail);}