C#、ASP.NET、WinForm

转载自：http://www.cnblogs.com/mingmingruyuedlut/archive/2011/10/14/2212255.html

发送邮件所用的核心知识点

微软封装好的MailMessage类：主要处理发送邮件的内容（如：收发人地址、标题、主体、图片等等）
微软封装好的SmtpClient类：主要处理用smtp方式发送此邮件的配置信息（如：邮件服务器、发送端口号、验证方式等等）
SmtpClient主要进行了三层的封装：Socket --> TcpClient --> SmtpClient
具体代码请看如下所示：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net.Mail;
using System.Net.Mime;
using System.IO;
using System.Timers;
using System.Xml;

namespace MyEmailTest
{
class Program
{
static void Main(string[] args)
{
try
{
//smtp.163.com
string senderServerIp = "123.125.50.133";
//smtp.gmail.com
//string senderServerIp = "74.125.127.109";
//smtp.qq.com
//string senderServerIp = "58.251.149.147";
//string senderServerIp = "smtp.sina.com";
string toMailAddress = "mingmingruyuedlut@163.com";
string fromMailAddress = "mingmingruyuedlut@163.com";
string subjectInfo = "Test sending e_mail";
string bodyInfo = "Hello Eric, This is my first testing e_mail";
string mailUsername = "mingmingruyuedlut";
string mailPassword = ".........."; //发送邮箱的密码（）
string mailPort = "25";
string attachPath = "E:123123.txt; E:haha.pdf";

            MyEmail email = new MyEmail(senderServerIp, toMailAddress, fromMailAddress, subjectInfo, bodyInfo, mailUsername, mailPassword, mailPort, false, false);
            email.AddAttachments(attachPath);
            email.Send();
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.ToString());
        }
    }
}

public class MyEmail
{
    private MailMessage mMailMessage;   //主要处理发送邮件的内容（如：收发人地址、标题、主体、图片等等）
    private SmtpClient mSmtpClient; //主要处理用smtp方式发送此邮件的配置信息（如：邮件服务器、发送端口号、验证方式等等）
    private int mSenderPort;   //发送邮件所用的端口号（htmp协议默认为25）
    private string mSenderServerHost;    //发件箱的邮件服务器地址（IP形式或字符串形式均可）
    private string mSenderPassword;    //发件箱的密码
    private string mSenderUsername;   //发件箱的用户名（即@符号前面的字符串，例如：hello@163.com，用户名为：hello）
    private bool mEnableSsl;    //是否对邮件内容进行socket层加密传输
    private bool mEnablePwdAuthentication;  //是否对发件人邮箱进行密码验证

    ///<summary>
    /// 构造函数
    ///</summary>
    ///<param name="server">发件箱的邮件服务器地址</param>
    ///<param name="toMail">收件人地址（可以是多个收件人，程序中是以“;"进行区分的）</param>
    ///<param name="fromMail">发件人地址</param>
    ///<param name="subject">邮件标题</param>
    ///<param name="emailBody">邮件内容（可以以html格式进行设计）</param>
    ///<param name="username">发件箱的用户名（即@符号前面的字符串，例如：hello@163.com，用户名为：hello）</param>
    ///<param name="password">发件人邮箱密码</param>
    ///<param name="port">发送邮件所用的端口号（htmp协议默认为25）</param>
    ///<param name="sslEnable">true表示对邮件内容进行socket层加密传输，false表示不加密</param>
    ///<param name="pwdCheckEnable">true表示对发件人邮箱进行密码验证，false表示不对发件人邮箱进行密码验证</param>
    public MyEmail(string server, string toMail, string fromMail, string subject, string emailBody, string username, string password, string port, bool sslEnable, bool pwdCheckEnable)
    {
        try
        {
            mMailMessage = new MailMessage();
            mMailMessage.To.Add(toMail);
            mMailMessage.From = new MailAddress(fromMail);
            mMailMessage.Subject = subject;
            mMailMessage.Body = emailBody;
            mMailMessage.IsBodyHtml = true;
            mMailMessage.BodyEncoding = System.Text.Encoding.UTF8;
            mMailMessage.Priority = MailPriority.Normal;
            this.mSenderServerHost = server;
            this.mSenderUsername = username;
            this.mSenderPassword = password;
            this.mSenderPort = Convert.ToInt32(port);
            this.mEnableSsl = sslEnable;
            this.mEnablePwdAuthentication = pwdCheckEnable;
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.ToString());
        }
    }

    ///<summary>
    /// 添加附件
    ///</summary>
    ///<param name="attachmentsPath">附件的路径集合，以分号分隔</param>
    public void AddAttachments(string attachmentsPath)
    {
        try
        {
            string[] path = attachmentsPath.Split(';'); //以什么符号分隔可以自定义
            Attachment data;
            ContentDisposition disposition;
            for (int i = 0; i < path.Length; i++)
            {
                data = new Attachment(path[i], MediaTypeNames.Application.Octet);
                disposition = data.ContentDisposition;
                disposition.CreationDate = File.GetCreationTime(path[i]);
                disposition.ModificationDate = File.GetLastWriteTime(path[i]);
                disposition.ReadDate = File.GetLastAccessTime(path[i]);
                mMailMessage.Attachments.Add(data);
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.ToString());
        }
    }

    ///<summary>
    /// 邮件的发送
    ///</summary>
    public void Send()
    {
        try
        {
            if (mMailMessage != null)
            {
                mSmtpClient = new SmtpClient();
                //mSmtpClient.Host = "smtp." + mMailMessage.From.Host;
                mSmtpClient.Host = this.mSenderServerHost;
                mSmtpClient.Port = this.mSenderPort;
                mSmtpClient.UseDefaultCredentials = false;
                mSmtpClient.EnableSsl = this.mEnableSsl;
                if (this.mEnablePwdAuthentication)
                {
                    System.Net.NetworkCredential nc = new System.Net.NetworkCredential(this.mSenderUsername, this.mSenderPassword);
                    //mSmtpClient.Credentials = new System.Net.NetworkCredential(this.mSenderUsername, this.mSenderPassword);
                    //NTLM: Secure Password Authentication in Microsoft Outlook Express
                    mSmtpClient.Credentials = nc.GetCredential(mSmtpClient.Host, mSmtpClient.Port, "NTLM");
                }
                else
                {
                    mSmtpClient.Credentials = new System.Net.NetworkCredential(this.mSenderUsername, this.mSenderPassword);
                }
                mSmtpClient.DeliveryMethod = System.Net.Mail.SmtpDeliveryMethod.Network;
                mSmtpClient.Send(mMailMessage);
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.ToString());
        }
    }
}

}

要开启邮箱的SmTP服务。