MailMessage mailMsg = new MailMessage(); 
  //设置收件人的邮件地址 
  mailMsg.To = "[email protected] "; 
   
  //设置发送者的邮件地址 
  mailMsg.From = "[email protected] "; 
  //设置邮件主题 
  mailMsg.Subject = "测试 "; 
   
  //设置邮件内容 
  mailMsg.Body = "内容 ";
  mailMsg.BodyFormat = MailFormat.Text;
  mailMsg.Priority = MailPriority.Normal;
  try
  {
  //设置发送邮件服务器 
  SmtpMail.SmtpServer = "localhost";
  //发送邮件 
  SmtpMail.Send(mailMsg);
  }
  catch
  {
  }
 
//一款完整发送邮件代码
MailObj _mail = new MailObj();
        _mail.sendMail("[email protected]", "测试", "<b>内容</b>");
        _mail.Dispose();
//核心代码
using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Collections.Generic;
using System.Net.Mail;
using System.Text;
namespace EC
{
    /// <summary>
    ///邮件发送
    /// </summary>
    public class MailObj
    {
        private string _strHost = string.Empty;
        private string _strAccount = string.Empty;
        private string _strPwd = string.Empty;
        private string _strFrom = string.Empty;
        #region 构造与析构函数
        public MailObj()
        {
            _strHost = "smtp.163.com";   //STMP服务器地址
            _strAccount = "aa";       //SMTP服务帐号
            _strPwd = "123456";       //SMTP服务密码
            _strFrom = "[email protected]";  //发送方邮件地址
        }
        /// <summary>
        /// 发送邮件购造函数
        /// </summary>
        /// <param name="strHost">STMP服务器地址:smtp.163.com</param>
        /// <param name="strAccount">SMTP服务帐号:liugongxun</param>
        /// <param name="strPwd">SMTP服务密码:123456</param>
        /// <param name="strFrom">发送方邮件地址:[email protected]</param>
        public MailObj(string strHost, string strAccount, string strPwd, string strFrom)
        {
            _strHost = strHost;
            _strAccount = strAccount;
            _strPwd = strPwd;
            _strFrom = strFrom;
        }

        ~MailObj()
        {
            Dispose();
        }
        public void Dispose()
        {
            GC.SuppressFinalize(this);
        }
        #endregion
        #region 发送邮件
        public bool sendMail(string to, string title, string content)
        {
            SmtpClient _smtpClient = new SmtpClient();
            _smtpClient.DeliveryMethod = SmtpDeliveryMethod.Network;//指定电子邮件发送方式
            _smtpClient.Host = _strHost;//指定SMTP服务器
            _smtpClient.Credentials = new System.Net.NetworkCredential(_strAccount, _strPwd);//用户名和密码
            MailMessage _mailMessage = new MailMessage(_strFrom, to);
            _mailMessage.Subject = title;//主题
            _mailMessage.Body = content;//内容
            _mailMessage.BodyEncoding = System.Text.Encoding.UTF8;//正文编码
            _mailMessage.IsBodyHtml = true;//设置为HTML格式
            _mailMessage.Priority = MailPriority.High;//优先级
            try
            {
                _smtpClient.Send(_mailMessage);
                return true;
            }
            catch
            {
                return false;
            }
        }
        #endregion
    }
}