本部落格主要利用C#中System.Net.Mail中的MailMessage 類進行郵件的傳送。話不多說直接上程式碼：

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Linq;
using System.Web;
using System.Reflection;
using System.Net;
using System.Net.Mail;
using System.Security.Cryptography.X509Certificates;
using System.Net
 
.Security;
using System.Net.Mime;

類主體如下：

/// <summary>
/// 傳送內郵(收件人、抄送人、附件若有多個，用分號[;]隔開)
/// </summary>
/// <param name="toMail">收件人</param>
/// <param name="ccMail">抄送人</param>
/// <param name="subject">郵件主題</param>
/// <param name="content">郵件內容</param>
/// <param name="filepath">
 
附件路徑</param>
public static bool SendMail(string toMail, string ccMail, string subject, string content, string filepath)
{
     try
            {
                var emailAcount = ConfigurationManager.AppSettings["EmailAcount"];
                var emailPassword = ConfigurationManager.AppSettings["EmailPassword"
 
];
                var emailServer = ConfigurationManager.AppSettings["SMTPServer"];
                var emailServerPort = ConfigurationManager.AppSettings["SMTPServerPort"];
                MailMessage message = new MailMessage();
                //設定發件人,163郵箱為例,需要在Web.config中進行配置
                MailAddress fromAddr = new MailAddress(string.Format("{0}@163.com", emailAcount));
                message.From = fromAddr;

                //遍歷收件人郵箱地址     
                if (toMail.Trim().Length != 0)
                {
                    string[] receivers = toMail.Trim().Split(';');
                    for (int i = 0; i < receivers.Length; i++)
                    {
                        if (receivers[i].Length > 0)
                        {
                            message.To.Add(receivers[i]);//為該郵件新增聯絡人  
                        }
                    }
                }
                //遍歷抄送人郵箱地址
                if (ccMail.Trim().Length != 0)
                {
                    string[] ccreceivers = ccMail.Trim().Split(';');
                    for (int j = 0; j < ccreceivers.Length; j++)
                    {
                        if (ccreceivers[j].Length > 0)
                        {
                            message.CC.Add(ccreceivers[j]);//為該郵件新增抄送人  
                        }
                    }
                }
                //設定郵件標題
                message.Subject = subject;
                //設定郵件內容
                message.Body = content;

                //新增附件
                if(filepath.Trim().Length != 0)
                {
                    string[] attachFiles = filepath.Trim().Split(';');
                    for(int k = 0; k < attachFiles.Length; k++)
                    {
                        if (attachFiles[k].Length > 0)
                        {
                            Attachment data = new Attachment(attachFiles[k], MediaTypeNames.Application.Octet);
                            message.Attachments.Add(data);
                        }
                    }
                }

                //設定郵件SMTP伺服器
                //SmtpClient client = new SmtpClient("smtp.163.com", 25);
                SmtpClient client = new SmtpClient(emailServer, Convert.ToInt32(emailServerPort));
                //設定傳送人的郵箱賬號和密碼
                client.Credentials = new NetworkCredential(emailAcount, emailPassword);
                //啟用ssl,也就是安全傳送
                client.EnableSsl = true;
                ServicePointManager.ServerCertificateValidationCallback =
    delegate(Object obj, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors) { return true; };
                //傳送郵件
                client.Send(message);
                return true;
            }
            catch (Exception ex)
            {
                log.Error("SendMail()", ex);
                return false;
            }
}