using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

//添加的命名空间引用

using System.Net;

using System.Net.Mail;

using System.IO;

using System.Net.Mime;

namespace SendMailExample

{

    public partial class FormSendMail : Form

    {

        public FormSendMail()

        {

            InitializeComponent();

        }

        private void FormSendMail_Load(object sender, EventArgs e)

        {

            //邮箱协议

            textBoxSmtpServer.Text = "smtp.qq.com";

            //发送人邮箱

            textBoxSend.Text = "邮箱账号";

            //发送人姓名

            textBoxDisplayName.Text = "名字";

            //密码

            textBoxPassword.Text = "邮箱密码";

            //收件人姓名

            textBoxReceive.Text = "收件人邮箱账号";

            //发送标题

            textBoxSubject.Text = "测试mytest";

            //发送内容

            textBoxBody.Text = "This is a test（测试）";

            radioButtonSsl.Checked = true;

        }

        //单击【发送】按钮触发的事件

        private void buttonSend_Click(object sender, EventArgs e)

        {

            this.Cursor = Cursors.WaitCursor;

            //实例化一个发送邮件类

            MailMessage mailMessage = new MailMessage();

            //发件人邮箱，方法重载不同，可以根据需求自行选择

            mailMessage.From = new MailAddress(textBoxSend.Text, textBoxDisplayName.Text, System.Text.Encoding.UTF8);

            //收件人邮箱地址

            mailMessage.To.Add(textBoxReceive.Text);

            //邮件标题

            mailMessage.Subject = textBoxSubject.Text;

            //邮件发送使用的编码

            mailMessage.SubjectEncoding = System.Text.Encoding.Default;

            //邮件发送的内容

            mailMessage.Body = textBoxBody.Text;

            //发送邮件的标题

            mailMessage.BodyEncoding = System.Text.Encoding.Default;

            //指定邮件是否为html格式

            mailMessage.IsBodyHtml = false;

            //设置电子邮件的优先级

            mailMessage.Priority = MailPriority.Normal;

            //添加附件

            Attachment attachment = null;

            if (listBoxFileName.Items.Count > )

            {

                for (int i = ; i < listBoxFileName.Items.Count; i++)

                {

                    string pathFileName = listBoxFileName.Items[i].ToString();

                    string extName = Path.GetExtension(pathFileName).ToLower();

                    //这里仅举例说明如何判断附件类型

                    if (extName == ".rar" || extName == ".zip")

                    {

                        attachment = new Attachment(pathFileName, MediaTypeNames.Application.Zip);

                    }

                    else

                    {

                        attachment = new Attachment(pathFileName, MediaTypeNames.Application.Octet);

                    }

                    ContentDisposition cd = attachment.ContentDisposition;

                    cd.CreationDate = File.GetCreationTime(pathFileName);

                    cd.ModificationDate = File.GetLastWriteTime(pathFileName);

                    cd.ReadDate = File.GetLastAccessTime(pathFileName);

                    mailMessage.Attachments.Add(attachment);

                }

            }

            SmtpClient smtpClient = new SmtpClient();

            smtpClient.Host = textBoxSmtpServer.Text;

            smtpClient.Port = ;

            //是否使用安全套接字层加密连接

            smtpClient.EnableSsl = radioButtonSsl.Checked;

            //不使用默认凭证,注意此句必须放在client.Credentials的上面

            smtpClient.UseDefaultCredentials = false;

            smtpClient.Credentials = new NetworkCredential(textBoxSend.Text, textBoxPassword.Text);

            //邮件通过网络直接发送到服务器

            smtpClient.DeliveryMethod = SmtpDeliveryMethod.Network;

            try

            {

                smtpClient.Send(mailMessage);

                MessageBox.Show("发送成功");

            }

            catch (SmtpException smtpError)

            {

                MessageBox.Show("发送失败:" + smtpError.StatusCode

                    + "\n\n" + smtpError.Message

                    + "\n\n" + smtpError.StackTrace);

            }

            finally

            {

                mailMessage.Dispose();

                smtpClient = null;

                this.Cursor = Cursors.Default;

            }

        }

        //单击【添加附件】按钮触发的事件

        private void buttonAddAttachment_Click(object sender, EventArgs e)

        {

            //提示用户打开一个文件夹

            OpenFileDialog myOpenFileDialog = new OpenFileDialog();

            myOpenFileDialog.CheckFileExists = true;

            //只接收有效的文件名

            myOpenFileDialog.ValidateNames = true;

            //允许一次选择多个文件作为附件

            myOpenFileDialog.Multiselect = true;

            myOpenFileDialog.ShowDialog();

            if (myOpenFileDialog.FileNames.Length > )

            {

                listBoxFileName.Items.AddRange(myOpenFileDialog.FileNames);

            }

        }

    }

}

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

//添加的命名空间引用

using System.Net;

using System.Net.Sockets;

using System.IO;

namespace ReceiveMailExample

{

    public partial class FormReceiveMail : Form

    {

        private TcpClient tcpClient;

        private NetworkStream networkStream;

        private StreamReader sr;

        private StreamWriter sw;

        public FormReceiveMail()

        {

            InitializeComponent();

            textBoxPOP3Server.Text = "pop.qq.com";

            textBoxPassword.Text = "密码";

            textBoxUser.Text = "邮箱账号";

        }

        //单击建立连接按钮触发的事件

        private void buttonConnect_Click(object sender, EventArgs e)

        {

            Cursor.Current = Cursors.WaitCursor;

            listBoxStatus.Items.Clear();

            try

            {

                //建立与POP3服务器的连接，使用默认端口110

                tcpClient = new TcpClient(textBoxPOP3Server.Text,);

                listBoxStatus.Items.Add("与pop3服务器连接成功");

            }

            catch

            {

                MessageBox.Show("与服务器连接失败");

                return;

            }

            string str;

            networkStream = tcpClient.GetStream();

            //得到输入流

            sr = new StreamReader(networkStream, Encoding.Default);

            //得到输出流

            sw = new StreamWriter(networkStream, Encoding.Default);

            sw.AutoFlush = true;

            //读取服务器回送的连接信息

            str = GetResponse();

            if (CheckResponse(str) == false) return;

            //向服务器发送用户名，请求确认

            SendToServer("USER " + textBoxUser.Text);

            str = GetResponse();

            if (CheckResponse(str) == false) return;

            //向服务器发送密码，请求确认

            SendToServer("PASS " + textBoxPassword.Text);

            str = GetResponse();

            if (CheckResponse(str) == false) return;

            //向服务器发送LIST命令，请求获取邮件总数和总字节数

            SendToServer("LIST");

            str = GetResponse();

            if (CheckResponse(str) == false) return;

            string[] splitString = str.Split(' ');

            //从字符串中取子串获取邮件总数

            int count = int.Parse(splitString[]);

            //判断邮箱中是否有邮件

            if (count > )

            {

                listBoxOperation.Items.Clear();

                groupBoxOperation.Text = "信箱中共有 " + splitString[] + " 封邮件";

                //向邮件列表框中添加邮件

                for (int i = ; i < count; i++)

                {

                    str = GetResponse();

                    splitString = str.Split(' ');

                    listBoxOperation.Items.Add(string.Format(

                        "第{0}封：{1}字节", splitString[], splitString[]));

                }

                listBoxOperation.SelectedIndex = ;

                //读出结束符

                str = GetResponse();

                //设置对应状态信息

                buttonRead.Enabled = true;

                buttonDelete.Enabled = true;

            }

            else

            {

                groupBoxOperation.Text = "信箱中没有邮件";

                buttonRead.Enabled = false;

                buttonDelete.Enabled = false;

            }

            buttonConnect.Enabled = false;

            buttonDisconnect.Enabled = true;

            Cursor.Current = Cursors.Default;

        }

        private bool SendToServer(string str)

        {

            try

            {

                sw.WriteLine(str);

                sw.Flush();

                listBoxStatus.Items.Add("发送：" + str);

                return true;

            }

            catch (Exception err)

            {

                listBoxStatus.Items.Add("发送失败：" + err.Message);

                return false;

            }

        }

        private string GetResponse()

        {

            string str = null;

            try

            {

                str = sr.ReadLine();

                if (str == null)

                {

                    listBoxStatus.Items.Add("收到：null");

                }

                else

                {

                    listBoxStatus.Items.Add("收到：" + str);

                    if (str.StartsWith("-ERR"))

                    {

                        str = null;

                    }

                }

            }

            catch (Exception ex)

            {

                listBoxStatus.Items.Add("接收失败：" + ex.Message);

            }

            return str;

        }

        private bool CheckResponse(string responseString)

        {

            if (responseString == null)

            {

                return false;

            }

            else

            {

                if (responseString.StartsWith("+OK"))

                {

                    return true;

                }

                else

                {

                    return false;

                }

            }

        }

        //单击断开连接按钮触发的事件

        private void buttonDisconnect_Click(object sender, EventArgs e)

        {

            SendToServer("QUIT");

            sr.Close();

            sw.Close();

            networkStream.Close();

            tcpClient.Close();

            listBoxOperation.Items.Clear();

            richTextBoxOriginalMail.Clear();

            listBoxStatus.Items.Clear();

            groupBoxOperation.Text = "邮件信息";

            buttonConnect.Enabled = true;

            buttonDisconnect.Enabled = false;

        }

        //单击阅读信件按钮触发的事件

        private void buttonRead_Click(object sender, EventArgs e)

        {

            Cursor.Current = Cursors.WaitCursor;

            richTextBoxOriginalMail.Clear();

            string mailIndex = listBoxOperation.SelectedItem.ToString();

            mailIndex = mailIndex.Substring(, mailIndex.IndexOf("封") - );

            SendToServer("RETR " + mailIndex);

            string str = GetResponse();

            if (CheckResponse(str) == false) return;

            try

            {

                string receiveData = sr.ReadLine();

                if (receiveData.StartsWith("-ERR") == true)

                {

                    listBoxStatus.Items.Add(receiveData);

                }

                else

                {

                    while (receiveData != ".")

                    {

                        richTextBoxOriginalMail.AppendText(receiveData + "\r\n");

                        receiveData = sr.ReadLine();

                    }

                }

            }

            catch (InvalidOperationException err)

            {

                listBoxStatus.Items.Add("Error: " + err.ToString());

            }

            Cursor.Current = Cursors.Default;

        }

        private void DecodeMailHeader(string mail)

        {

            string header = "";

            int pos = mail.IndexOf("\n\n");

            if (pos == -)

            {

                header = GetDecodedHeader(mail);

            }

            else

            {

                header = mail.Substring(, pos + );

            }

            //richTextBoxDecode.AppendText(GetDecodedHeader(header));

        }

        private string GetDecodedHeader(string header)

        {

            StringBuilder s = new StringBuilder();

            s.AppendLine("Subject:" + GetEncodedValueString(header, "Subject: ", false));

            s.AppendLine("From:" + GetEncodedValueString(header, "From: ", false).Trim());

            s.AppendLine("To:" + GetEncodedValueString(header, "To: ", true).Trim());

            s.AppendLine("Date:" + GetDateTimeFromString(GetValueString(header, "Date: ", false, false)));

            s.AppendLine("Cc:" + GetEncodedValueString(header, "Cc: ", true).Trim());

            s.AppendLine("ContentType:" + GetValueString(header, "Content-Type: ", false, true));

            return s.ToString();

        }

        /// <summary>

        /// 把时间转成字符串形式

        /// </summary>

        /// <param name="DateTimeString"></param>

        /// <returns></returns>

        private string GetDateTimeFromString(string DateTimeString)

        {

            if (DateTimeString == "")

            {

                return null;

            }

            try

            {

                string strDateTime;

                if (DateTimeString.IndexOf("+") != -)

                {

                    strDateTime = DateTimeString.Substring(, DateTimeString.IndexOf("+"));

                }

                else if (DateTimeString.IndexOf("-") != -)

                {

                    strDateTime = DateTimeString.Substring(, DateTimeString.IndexOf("-"));

                }

                else

                {

                    strDateTime = DateTimeString;

                }

                DateTime dt = DateTime.Parse(strDateTime);

                return dt.ToString();

            }

            catch

            {

                return null;

            }

        }

        private string GetEncodedValueString(string SourceString, string Key, bool SplitBySemicolon)

        {

            int j;

            string strValue;

            string strSource = SourceString.ToLower();

            string strReturn = "";

            j = strSource.IndexOf(Key.ToLower());

            if (j != -)

            {

                j += Key.Length;

                int kk = strSource.IndexOf("\n", j);

                strValue = SourceString.Substring(j, kk - j).TrimEnd();

                do

                {

                    if (strValue.IndexOf("=?") != -)

                    {

                        if (SplitBySemicolon == true)

                        {

                            strReturn += ConvertStringEncodingFromBase64(strValue) + "; ";

                        }

                        else

                        {

                            strReturn += ConvertStringEncodingFromBase64(strValue);

                        }

                    }

                    else

                    {

                        strReturn += strValue;

                    }

                    j += strValue.Length + ;

                    if (strSource.IndexOf("\r\n", j) == -)

                    {

                        break;

                    }

                    else

                    {

                        strValue = SourceString.Substring(j, strSource.IndexOf("\r\n", j) - j).TrimEnd();

                    }

                }

                while (strValue.StartsWith(" ") || strValue.StartsWith("\t"));

            }

            else

            {

                strReturn = "";

            }

            return strReturn;

        }

        private string GetValueString(string SourceString, string Key, bool ContainsQuotationMarks, bool ContainsSemicolon)

        {

            int j;

            string strReturn;

            string strSource = SourceString.ToLower();

            j = strSource.IndexOf(Key.ToLower());

            if (j != -)

            {

                j += Key.Length;

                strReturn = SourceString.Substring(j, strSource.IndexOf("\n", j) - j).TrimStart().TrimEnd();

                if (ContainsSemicolon == true)

                {

                    if (strReturn.IndexOf(";") != -)

                    {

                        strReturn = strReturn.Substring(, strReturn.IndexOf(";"));

                    }

                }

                if (ContainsQuotationMarks == true)

                {

                    int i = strReturn.IndexOf("\"");

                    int k;

                    if (i != -)

                    {

                        k = strReturn.IndexOf("\"", i + );

                        if (k != -)

                        {

                            strReturn = strReturn.Substring(i + , k - i - );

                        }

                        else

                        {

                            strReturn = strReturn.Substring(i + );

                        }

                    }

                }

                return strReturn;

            }

            else

            {

                return "";

            }

        }

        private string ConvertStringEncodingFromBase64(string SourceString)

        {

            try

            {

                if (SourceString.IndexOf("=?") == -)

                {

                    return SourceString;

                }

                else

                {

                    int i = SourceString.IndexOf("?");

                    int j = SourceString.IndexOf("?", i + );

                    int k = SourceString.IndexOf("?", j + );

                    char chrTransEnc = SourceString[j + ];

                    switch (chrTransEnc)

                    {

                        case 'B':

                            return ConvertStringEncodingFromBase64Ex(SourceString.Substring(k + , SourceString.IndexOf("?", k + ) - k - ), SourceString.Substring(i + , j - i - ));

                        default:

                            throw new Exception("unhandled content transfer encoding");

                    }

                }

            }

            catch

            {

                return "";

            }

        }

        /// <summary>

        /// 把Base64编码转换成字符串

        /// </summary>

        /// <param name="SourceString"></param>

        /// <param name="Charset"></param>

        /// <returns></returns>

        private string ConvertStringEncodingFromBase64Ex(string SourceString, string Charset)

        {

            try

            {

                Encoding enc;

                if (Charset == "")

                    enc = Encoding.Default;

                else

                    enc = Encoding.GetEncoding(Charset);

                return enc.GetString(Convert.FromBase64String(SourceString));

            }

            catch

            {

                return "";

            }

        }

        /// <summary>

        /// 把字符串转换成Base64Ex编码

        /// </summary>

        /// <param name="SourceString"></param>

        /// <param name="Charset"></param>

        /// <param name="AutoWordWrap"></param>

        /// <returns></returns>

        private string ConvertStringEncodingToBase64Ex(string SourceString, string Charset, bool AutoWordWrap)

        {

            Encoding enc = Encoding.GetEncoding(Charset);

            byte[] buffer = enc.GetBytes(SourceString);

            string strContent = Convert.ToBase64String(buffer);

            StringBuilder strTemp = new StringBuilder();

            int ii = ;

            for (int i = ; i <= strContent.Length /  - ; i++)

            {

                strTemp.Append(strContent.Substring( * i, ) + "\r\n");

                ii++;

            }

            strTemp.Append(strContent.Substring( * (ii)));

            strContent = strTemp.ToString();

            return strContent;

        }

        private string ConvertStringEncoding(string SourceString, string Charset)

        {

            try

            {

                Encoding enc;

                if (Charset == "8bit" || Charset == "")

                {

                    enc = Encoding.Default;

                }

                else

                {

                    enc = Encoding.GetEncoding(Charset);

                }

                return enc.GetString(Encoding.ASCII.GetBytes(SourceString));

            }

            catch

            {

                return Encoding.Default.GetString(Encoding.ASCII.GetBytes(SourceString));

            }

        }

        //单击删除信件按钮触发的事件

        private void buttonDelete_Click(object sender, EventArgs e)

        {

            string parameter = listBoxOperation.SelectedItem.ToString();

            parameter = parameter.Substring(, parameter.IndexOf("封") - );

            SendToServer("DELE " + parameter);

            string str = GetResponse();

            if (CheckResponse(str) == false) return;

            richTextBoxOriginalMail.Clear();

            int j = listBoxOperation.SelectedIndex;

            listBoxOperation.Items.Remove(listBoxOperation.Items[j].ToString());

            MessageBox.Show("删除成功");

        }

    }

}