c# 邮件发送

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Net.Mail;
using System.Net;
using System.Text;

public partial class SendEmail : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        SendMail(); 
    }

    private void SendMail()
    {
        string FromMial = "";
        string ToMial = "";
        string AuthorizationCode = "";
        string ReplyTo = null;
        string CCMial = null;
        string File_Path = null;

        SendMail(FromMial, ToMial, AuthorizationCode, ReplyTo, CCMial, File_Path);
    }

    private void SendMailFrom163ToQQ()
    {
        string FromMial = "18602702011@163.com";
        string ToMial = "172237218@qq.com";
        string AuthorizationCode = "guohu@2003";
        string ReplyTo = null;
        string CCMial = null;
        string File_Path = null;

        SendMail(FromMial, ToMial, AuthorizationCode, ReplyTo, CCMial, File_Path);
    }


    /// <summary>
    /// 发送邮件方法
    /// </summary>
    /// <param name="FromMial">发件人邮箱</param>
    /// <param name="ToMial">收件人邮箱(多个收件人地址用";"号隔开)</param>
    /// <param name="AuthorizationCode">发件人授权码</param>
    /// <param name="ReplyTo">对方回复邮件时默认的接收地址（不设置也是可以的）</param>
    /// <param name="CCMial">//邮件的抄送者(多个抄送人用";"号隔开)</param>
    /// <param name="File_Path">附件的地址</param>
    public void SendMail(string FromMial, string ToMial, string AuthorizationCode, string ReplyTo, string CCMial, string File_Path)
    {
        try
        {
            //实例化一个发送邮件类。
            MailMessage mailMessage = new MailMessage();

            //邮件的优先级，分为 Low, Normal, High，通常用 Normal即可
            mailMessage.Priority = MailPriority.Normal;

            //发件人邮箱地址。
            mailMessage.From = new MailAddress(FromMial);

            //收件人邮箱地址。需要群发就写多个
            //拆分邮箱地址
            List<string> ToMiallist = ToMial.Split(';').ToList();
            for (int i = 0; i < ToMiallist.Count; i++)
            {
                mailMessage.To.Add(new MailAddress(ToMiallist[i]));  //收件人邮箱地址。
            }

            if (ReplyTo == "" || ReplyTo == null)
            {
                ReplyTo = FromMial;
            }

            //对方回复邮件时默认的接收地址(不设置也是可以的哟)
            mailMessage.ReplyTo = new MailAddress(ReplyTo);

            if (CCMial != "" && CCMial != null)
            {
                List<string> CCMiallist = ToMial.Split(';').ToList();
                for (int i = 0; i < CCMiallist.Count; i++)
                {
                    //邮件的抄送者，支持群发
                    mailMessage.CC.Add(new MailAddress(CCMial));
                }
            }
            //如果你的邮件标题包含中文，这里一定要指定，否则对方收到的极有可能是乱码。
            mailMessage.SubjectEncoding = Encoding.GetEncoding(936);

            //邮件正文是否是HTML格式
            mailMessage.IsBodyHtml = false;

            //邮件标题。
            mailMessage.Subject = "发送邮件测试";
            //邮件内容。
            mailMessage.Body = "测试群发邮件,以及附件邮件！.....";

            //设置邮件的附件，将在客户端选择的附件先上传到服务器保存一个，然后加入到mail中  
            if (File_Path != "" && File_Path != null)
            {
                //将附件添加到邮件
                mailMessage.Attachments.Add(new Attachment(File_Path));
                //获取或设置此电子邮件的发送通知。
                mailMessage.DeliveryNotificationOptions = DeliveryNotificationOptions.OnSuccess;
            }

            //实例化一个SmtpClient类。
            SmtpClient client = new SmtpClient();

            #region 设置邮件服务器地址

            //在这里我使用的是163邮箱，所以是smtp.163.com，如果你使用的是qq邮箱，那么就是smtp.qq.com。
            // client.Host = "smtp.163.com";
            if (FromMial.Length != 0)
            {
                //根据发件人的邮件地址判断发件服务器地址   默认端口一般是25  
                string[] addressor = FromMial.Trim().Split(new Char[] { '@', '.' });
                switch (addressor[1])
                {
                    case "163":
                        client.Host = "smtp.163.com";
                        break;
                    case "126":
                        client.Host = "smtp.126.com";
                        break;
                    case "qq":
                        client.Host = "smtp.qq.com";
                        break;
                    case "gmail":
                        client.Host = "smtp.gmail.com";
                        break;
                    case "hotmail":
                        client.Host = "smtp.live.com";//outlook邮箱
                        //client.Port = 587;
                        break;
                    case "foxmail":
                        client.Host = "smtp.foxmail.com";
                        break;
                    case "sina":
                        client.Host = "smtp.sina.com.cn";
                        break;
                    case "chnenergy":
                        client.Host = "mail.chnenergy.com.cn"; 
                        client.Port = 465;
                        break;
                    default:
                        client.Host = "smtp.exmail.qq.com";//qq企业邮箱
                        break;
                }
            }
            #endregion

            //使用安全加密连接。
            client.EnableSsl = true;
            //不和请求一块发送。
            client.UseDefaultCredentials = false;

            //验证发件人身份(发件人的邮箱，邮箱里的生成授权码);
            client.Credentials = new NetworkCredential(FromMial, AuthorizationCode);

            //如果发送失败，SMTP 服务器将发送 失败邮件告诉我  
            mailMessage.DeliveryNotificationOptions = DeliveryNotificationOptions.OnFailure;
            //发送
            client.Send(mailMessage);
            Response.Write("发送成功"); 
        }
        catch (Exception ex)
        {
            throw new Exception(ex.Message);
        }
    }
}