C#利用System.Net发送邮件（带 抄送、密送、附件、html格式的邮件）

net2.0后，C#可以利用System.Net发送邮件了。

代码整理如下：

　3. 增加IProcessMessage类，定义了一个消息方法，用于消息传递

 /**************************************
 * <copyright file="SendEail.cs">
 * Copyright(c)2014 LeeStudio All rights reserved.
 * CLR版本：4.0.30319.17929
 * 开发团队：欺心伴月个人工作室
 * 技术博客：http://www.cnblogs.com/lichunyang/
 * 所属工程：LeeStudio.Basic
 * 创 建 者：Frank Lee
 * 修改时间：2014-02-20 11:20
 * </copyright>
 **************************************/

 using System;
 using System.Text;
 using System.Net;
 using System.Net.Mail;
 using System.Net.Mime;

 namespace LeeStudio.Basic
 {
 /// <summary>
 /// 邮件发送类
 /// </summary>
 public class SendEmail
 {
 private MailMessage mailMessage = new MailMessage(); //实例化一个邮件类

 #region 构造函数
 /// <summary>
 /// 构造函数
 /// </summary>
 /// <param name="toAddresses">收件人地址（多个以,号分开）</param>
 /// <param name="fromAddress">发件人地址</param>
 /// <param name="title">主题</param>
 /// <param name="body">正文</param>
 public SendEmail(string toAddresses, string fromAddress, string title, string body)
 : this(toAddresses, fromAddress, "", "", title, body, false)
 {
 }

 /// <summary>
 /// 构造函数
 /// </summary>
 /// <param name="toAddress">收件人地址</param>
 /// <param name="fromAddress">发件人地址</param>
 /// <param name="toName">收件人名字</param>
 /// <param name="fromName">发件人姓名</param>
 /// <param name="title">主题</param>
 /// <param name="body">正文</param>
 /// <param name="isBodyHtml">正文是否为html格式</param>
 public SendEmail(string toAddress, string fromAddress, string toName, string fromName, string title, string body, bool isBodyHtml)
 {
 mailMessage.From = new MailAddress(fromAddress, fromName, Encoding.GetEncoding());
 if (toName.Equals(""))
 mailMessage.To.Add(toAddress);
 else
 mailMessage.To.Add(new MailAddress(toAddress, toName, Encoding.GetEncoding()));

 mailMessage.Subject = title;
 mailMessage.SubjectEncoding = Encoding.GetEncoding();

 mailMessage.Body = body;
 mailMessage.IsBodyHtml = isBodyHtml;
 mailMessage.BodyEncoding = Encoding.GetEncoding();
 }
 #endregion

 /// <summary>
 /// 设置SMTP，并且将邮件发送出去
 /// 所有参数都设置完成后再调用该方法
 /// </summary>
 /// <param name="password">发件人密码</param>
 /// <param name="smtpHost">SMTP服务器地址</param>
 public void SetSmtp(string password, string smtpHost)
 {
 SetSmtp(mailMessage.From.Address, password, smtpHost, , false, MailPriority.Normal);
 }

 /// <summary>
 /// 设置SMTP，并且将邮件发送出去
 /// 所有参数都设置完成后再调用该方法
 /// </summary>
 /// <param name="address">发件人地址（必须为真实有效的email地址）</param>
 /// <param name="password">发件人密码</param>
 /// <param name="smtpHost">SMTP服务器地址</param>
 /// <param name="smtpPort">SMTP服务器的端口</param>
 /// <param name="isEnableSsl">SMTP服务器是否启用SSL加密</param>
 /// <param name="priority">邮件的优先级</param>
 public void SetSmtp(string address, string password, string smtpHost, int smtpPort, bool isEnableSsl, MailPriority priority)
 {
 SmtpClient smtp = new SmtpClient();
 smtp.DeliveryMethod = SmtpDeliveryMethod.Network;
 smtp.Credentials = new NetworkCredential(address, password);
 smtp.Host = smtpHost;
 smtp.Port = smtpPort;
 smtp.EnableSsl = isEnableSsl;

 mailMessage.Priority = priority;
 smtp.Send(mailMessage); //发送邮件
 }

 #region //设置邮件地址
 /// <summary>
 /// 设置更多收件人
 /// </summary>
 /// <param name="toAddresses">收件人地址</param>
 public void SetMoreToAddress(string toAddresses)
 {
 mailMessage.To.Add(toAddresses);
 }

 /// <summary>
 /// 设置更多收件人
 /// </summary>
 /// <param name="toAddresses">收件人地址</param>
 /// <param name="toName">收件人名字</param>
 public void SetMoreToAddress(string toAddress, string toName)
 {
 mailMessage.To.Add(new MailAddress(toAddress, toName, Encoding.GetEncoding()));
 }

 /// <summary>
 /// 设置抄送者（多个以,号分开）
 /// </summary>
 /// <param name="ccAddresses">抄送者地址</param>
 public void SetCarbonCopyFor(string ccAddresses)
 {
 mailMessage.CC.Add(ccAddresses);
 }

 /// <summary>
 /// 设置抄送者
 /// </summary>
 /// <param name="ccAddress">抄送者地址</param>
 /// <param name="ccName">抄送者名字</param>
 public void SetCarbonCopyFor(string ccAddress, string ccName)
 {
 mailMessage.Bcc.Add(new MailAddress(ccAddress, ccName, Encoding.GetEncoding()));
 }

 /// <summary>
 /// 设置密送者（多个以,号分开）
 /// </summary>
 /// <param name="bccAddresses">密送者</param>
 public void SetBlindCarbonCopyFor(string bccAddresses)
 {
 mailMessage.Bcc.Add(bccAddresses);
 }

 /// <summary>
 /// 设置密送者
 /// </summary>
 /// <param name="bccAddress">密送者</param>
 /// <param name="bccName">密送者名字</param>
 public void SetBlindCarbonCopyFor(string bccAddress, string bccName)
 {
 mailMessage.Bcc.Add(new MailAddress(bccAddress, bccName, Encoding.GetEncoding()));
 }
 #endregion

 #region 添加附件
 /// <summary>
 /// 添加附件（自动识别文件类型）
 /// </summary>
 /// <param name="fileName">单个文件的路径</param>
 public void Attachments(string fileName)
 {
 mailMessage.Attachments.Add(new Attachment(fileName));
 }

 /// <summary>
 /// 添加附件（默认为富文本RTF格式）
 /// </summary>
 /// <param name="fileName">单个文件的路径</param>
 public void AttachmentsForRTF(string fileName)
 {
 mailMessage.Attachments.Add(new Attachment(fileName, MediaTypeNames.Application.Rtf));
 }
 #endregion
 }
 }

调用是按照需求，自由设置参数。

 using LeeStudio.Basic;

 private void SendEmail()
 {
 #region 最简设置
 //SendEmail se = new SendEmail("*****@****.com", "****@163.com", "title", "body");
 //se.SetSmtp("password", "smtp.163.com"); //必须在所有参数设置完后调用此方法
 #endregion

 #region 完全设置
 //string toAddresses = "***@**.**,***@**.**";
 //string toNames = "frank,lee";

 //SendEmail se = new SendEmail("to@**.**", "from@**.**", "toname", "fromname","title", "body", false);
 //se.SetMoreToAddress("to@**.**", "toName");
 //se.SetCarbonCopyFor("cc@**.**");
 //se.SetBlindCarbonCopyFor("bcc@**.**");

 //string filePath = Request.PhysicalApplicationPath + "/file/SendEmail.txt";
 //se.Attachments(filePath);
 //filePath = Request.PhysicalApplicationPath + "/file/RTF文件.docx";
 //se.AttachmentsForRTF(filePath);
 //se.SetSmtp("email", "password", "smtp", 25, true, System.Net.Mail.MailPriority.Normal); //必须在所有参数设置完后调用此方法
 #endregion
 }

遗留问题：

当有多个收件人/抄送者/密送者时，如何快速处理？之前的做法是让用户输入字符串，再将字符串一一对应匹配，代码如下：

 /// <summary>
 /// 将邮件地址和名称加入到锯齿数组中
 /// </summary>
 /// <param name="addrs">邮件地址（多个以,号分开）</param>
 /// <param name="names">名称（多个以,号分开）</param>
 /// <returns>地址和名称数组</returns>
 private string[][] SetNameList(string addrs, string names)
 {
     string[][] result = new string[][];

     string[] addr = addrs.Split(',');
     string[] name = names.Split(',');
     result[] = new string[addr.Length];
     result[] = new string[name.Length];

     for (int i = ; i < addr.Length; i++)
         result[][i] = addr[i];
     for (int i = ; i < name.Length; i++)
         result[][i] = name[i];

     return result;
 }

首先这个方法就很奇葩，其次，只要用户输入的个数不对应，又要做一堆的异常处理。