基于POP3與SMTP協(xié)議的郵件收發(fā)程序的開發(fā)

1、基于POP3與SMTP協(xié)議的郵件收發(fā)程序的開發(fā)一、設計思想電子郵件指用電子手段傳送信件、單據(jù)、資料等信息的通信方法。電子郵件綜合了電話通信和郵政信件的特點，它傳送信息的速度和電話一樣快，又能象信件一樣使收信者在接收端收到文字記錄。電子郵件系統(tǒng)又稱基于計算機的郵件報文系統(tǒng)。它承擔從郵件進入系統(tǒng)到郵件到達目的地為止的全部處理過程。電子郵件不僅可利用電話網(wǎng)絡,而且可利用任何通信網(wǎng)傳送。在利用電話網(wǎng)絡時,還可利用其非高峰期間傳送信息，這對于商業(yè)郵件具有特殊價值。由中央計算機和小型計算機控制的面向有限用戶的電子系統(tǒng)可以看作是一種計算機會議系統(tǒng)。電子郵件的工作過程遵循客戶-服務器模式。每份電子郵件的發(fā)送都

2、要涉及到發(fā)送方與接收方，發(fā)送方式構(gòu)成客戶端，而接收方構(gòu)成服務器，服務器含有眾多用戶的電子信箱。發(fā)送方通過郵件客戶程序，將編輯好的電子郵件向郵局服務器（SMTP服務器）發(fā)送。郵局服務器識別接收者的地址，并向管理該地址的郵件服務器（POP3服務器）發(fā)送消息。 一個郵件系統(tǒng)的傳輸包含用戶代理User Agent傳輸代理TransferAgent及接受代理DeliveryAgent三大部分。 用戶代理是一個用戶發(fā)信和收信的程序,負責將電子郵件按照一定的標準包裝,然后送至郵件服務器,或由郵件服務器收回。傳輸代理負責信件的交換和傳輸。將信件傳送至適當?shù)泥]件主機,再由接受代理將信件分發(fā)至

3、不同的郵件信箱。傳輸代理必須要能夠接受用戶郵件程序送來的信件,解讀收信人的地址,根據(jù)SMTP協(xié)議將它正確無誤地傳遞到目的地?，F(xiàn)在一般的傳輸代理已采用Sendmail程序完成工作。電子郵件到達郵件主機后,在經(jīng)接收代理POP協(xié)議被用戶讀取至自己的主機。 電子郵件在發(fā)送與接收過程中都要遵循SMTP、POP3等協(xié)議，這些協(xié)議確保了電子郵件在各種不同系統(tǒng)之間的傳輸。其中，SMTP負責電子郵件的發(fā)送，而POP3則用于接收Internet上的電子郵件。 SMTP(Simple Mail Transfer Protocol)即簡單郵件傳輸協(xié)議,它是一組用于由源

4、地址到目的地址傳送郵件的規(guī)則,由它來控制信件的中轉(zhuǎn)方式。SMTP協(xié)議屬于TCPIP協(xié)議族,它幫助每臺計算機在發(fā)送或中轉(zhuǎn)信件時找到下一個目的地。通過SMTP協(xié)議所指定的服務器,我們就可以把Email寄到收信人的服務器上了,整個過程只要幾分鐘。SMTP服務器則是遵循SMTP協(xié)議的發(fā)送郵件服務器，用來發(fā)送或中轉(zhuǎn)你發(fā)出的電子郵件。POP3(Post Office Protocol 3)即郵局協(xié)議，目前已發(fā)展到第三版，稱POP3。它規(guī)定怎樣將個人計算機連接到Internet的郵件服務器和下載電子郵件的電子協(xié)議。它是因特網(wǎng)電子郵件的第一個離線協(xié)議標準,POP3允許用戶從服務器

5、上把郵件存儲到本地主機（即自己的計算機）上,同時刪除保存在郵件服務器上的郵件，而POP3服務器則是遵循POP3協(xié)議的接收郵件服務器，用來接收電子郵件的?？偟膩碚fPOP3協(xié)議是讓用戶把服務器上的信收到本地來所需要的一種協(xié)議。 本程序為一個基于SMTP和POP3協(xié)議的小型EMAIL收發(fā)程序，簡單的實現(xiàn)了郵件的收發(fā)功能。二、算法流程圖USERE-mail用戶操作SMTP協(xié)議POP3協(xié)議郵件服務器用戶登錄用戶信息郵件信息選擇郵件發(fā)送郵件接收郵件圖1 算法流程圖三、源代碼下面給出的是用登錄程序的源代碼：using System; /導入名字空間using System.Collections.

6、Generic; /包含定義各種對象集合的接口和類using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text; /包含表示 ASCII等字符編碼的類using System.Windows.Forms;using System.Net;using System.Net.Sockets;using System.IO;namespace MailSendOfRecive /命名空間public partial class Form3 : Form /定

7、義類public string Conn,Uname,Pwd,Inf; /定義用戶名、密碼public TcpClient Server; /定義服務器public NetworkStream NetStrm;public StreamReader RdStrm;public Boolean BPass; /定義BPasspublic string Data;public byte szData;public string CRLF = "rn" /定義快捷鍵public Form2 Sender;public Form3() /定義框架InitializeComponen

8、t(); /初始化private void Login_Click(object sender, EventArgs e)Conn = "pop."+textBox1.Text.Trim();Uname = textBox2.Text.Trim(); /用戶名Pwd = textBox3.Text; /密碼Server = new TcpClient(Conn, 110); /服務器tryNetStrm = Server.GetStream();RdStrm = new StreamReader(Server.GetStream(), System.Text.Encodin

9、g.Default);RdStrm.ReadLine();Data = "USER "+ Uname + CRLF;szData = System.Text.Encoding.ASCII.GetBytes(Data);/獲取ASCII值NetStrm.Write(szData,0,szData.Length);RdStrm.ReadLine(); /讀取字符并返回Data = "PASS "+ Pwd + CRLF;szData = System.Text.Encoding.ASCII.GetBytes(Data);NetStrm.Write(szDat

10、a,0,szData.Length);Inf = RdStrm.ReadLine();if (Inf.IndexOf("+OK")>-1)BPass = true; /布爾值設為真Sender = new Form2(Uname, Pwd, textBox1.Text);this.Hide();Sender.Show();else if (Inf.IndexOf("-OK")>-1) /判斷索引MessageBox.Show("密碼或者用戶名錯誤", "用戶驗證"); /文本框顯示信息Data = &q

11、uot;QUIT"szData = System.Text.Encoding.ASCII.GetBytes(Data);NetStrm.Write(szData, 0, szData.Length); /寫入數(shù)據(jù)catch (System.Exception ex)MessageBox.Show(ex.Message); /文本框顯示信息private void Form3_Load(object sender, EventArgs e)/定義Form3_Load下面是發(fā)送郵件程序源代碼using System; /導入名字空間using System.Collections.Gen

12、eric; /包含定義各種對象集合的接口和類using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text; /包含表示 ASCII等字符編碼的類using System.Windows.Forms;using System.Net;using System.Net.Sockets;using System.IO;using System.Collections;using System.Data.OleDb;namespace MailSendOfRe

13、cive /命名空間public partial class Form1 : Form /定義類TcpClient smtpSrv;NetworkStream netStm; /提供數(shù)據(jù)流string CRLF = "rn"public List<MailInfo> SMail = new List<MailInfo>();public Form2 fa;public string Ua, Pw, Sv;public Form1(Form2 f,string UN,string Pd,string SR) /創(chuàng)建Form1fa = f;Ua = UN

14、;Pw = Pd;Sv = SR;InitializeComponent(); /初始化public void WriteStream(string strCmd)strCmd += CRLF; /crlf表示結(jié)束byte bw = System.Text.Encoding.Default.GetBytes(strCmd); /將字符串轉(zhuǎn)為字節(jié)數(shù)組netStm.Write(bw,0,bw.Length); /寫入網(wǎng)絡private string AuthStream(string strCmd) /連接服務器輸出字符串trybyte by = System.Text.Encoding.Defa

15、ult.GetBytes(strCmd);strCmd = Convert.ToBase64String(by); /轉(zhuǎn)換成base64編碼catch (System.Exception ex)return ex.ToString();return strCmd;public bool tryTran( ref string a) /定義布爾變量string b = ""b = a;trybyte outputb = Convert.FromBase64String(a); /轉(zhuǎn)換數(shù)據(jù)類型a = Encoding.Default.GetString(outputb);ret

16、urn true;catch (System.Exception ex) /顯示錯誤a= b;return false;public void WritInf(string s) /定義WritInftryTran(ref s);listBoxMsg.Items.Add(s);private void ButtonSend_Click(object sender, EventArgs e) /定義ButtonSend_ClicklistBoxMsg.Items.Clear(); /存放smtp服務器返回的信息trystring data;progressBar1.Visible = true;

17、progressBar1.Value = 1;smtpSrv = new TcpClient("smtp."+Sv,25);/TextBoxSer.Text,25); /連接smtp服務器netStm = smtpSrv.GetStream(); /取得Networkstream對象,來發(fā)送接收數(shù)據(jù)StreamReader rdStrm = new StreamReader(smtpSrv.GetStream(); /產(chǎn)生StreamReader來讀取數(shù)據(jù)流WriteStream("EHLO Local"); /發(fā)送命令建立連接progressBar1.

18、Value+;listBoxMsg.Items.Add("輸入用戶名開始");WriteStream("AUTH LOGIN"); /發(fā)送命令請求驗證listBoxMsg.Items.Add(rdStrm.ReadLine();progressBar1.Value+;data = AuthStream(Ua);/data); /轉(zhuǎn)換編碼格式WriteStream(data); /發(fā)送用戶名listBoxMsg.Items.Add(rdStrm.ReadLine();data = AuthStream(Pw);/data); /轉(zhuǎn)換編碼格式WriteStr

19、eam(data); /發(fā)送listBoxMsg.Items.Add(rdStrm.ReadLine(); progressBar1.Value+;data = "MAIL FROM:<" + TextBoxSend.Text + ">" /發(fā)件人地址WriteStream(data);listBoxMsg.Items.Add(rdStrm.ReadLine();progressBar1.Value+;data = "RCPT TO:<"+TextBoxRev.Text+">" /收件人地址

20、WriteStream(data);listBoxMsg.Items.Add(rdStrm.ReadLine();progressBar1.Value+;WriteStream("DATA"); /數(shù)據(jù)listBoxMsg.Items.Add(rdStrm.ReadLine();progressBar1.Value+;data = "Date:"+System.DateTime.Now; /日期WriteStream(data);progressBar1.Value+;data = "From:" + TextBoxSend.Text

21、; /發(fā)送者WriteStream(data);progressBar1.Value+;data = "To:" + TextBoxRev.Text; /接收者WriteStream(data);progressBar1.Value+;data = "SUBJECT:" + textBoxSubject.Text; /主題WriteStream(data);progressBar1.Value+;data = "Reply-To:" + TextBoxSend.Text; /發(fā)送回復地址WriteStream(data);progre

22、ssBar1.Value+;WriteStream(""); /表示首部結(jié)束,開始正文progressBar1.Value+;WriteStream(textBoxMailText.Text);progressBar1.Value+;WriteStream("."); /點表示郵件內(nèi)容結(jié)束progressBar1.Value+;listBoxMsg.Items.Add(rdStrm.ReadLine();WriteStream("QUIT"); /斷開progressBar1.Value+;listBoxMsg.Items.Add(r

23、dStrm.ReadLine(); /添加項netStm.Close();rdStrm.Close(); /釋放資源MailInfo i = new MailInfo();i.sender = TextBoxSend.Text;i.geter = TextBoxRev.Text;i.Ttile = textBoxSubject.Text;i.NeiRong = textBoxMailText.Text;i.Datatime = DateTime.Now.ToString();/將發(fā)送的消息送到SMail便于傳個收件箱界面SMail.Add(i);MessageBox.Show("郵件

24、發(fā)送成功", "成功"); /顯示信息catch (System.Exception ex)MessageBox.Show(ex.ToString(), "操作錯誤"); /顯示信息private void Form1_FormClosed(object sender, FormClosedEventArgs e)Application.Exit(); /終止所有程序private void button1_Click(object sender, EventArgs e)this.Hide(); /隱藏控件fa.Show();fa.GetSe

25、nMail(SMail);private void Form1_Load(object sender, EventArgs e)下面是接收郵件程序源代碼using System; /導入名字空間using System.Collections.Generic; /包含定義各種對象集合的接口和類using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;using System.Net; /包含表示

26、 ASCII等字符編碼的類using System.Net.Mail;using System.Net.Sockets;using System.IO;using System.Collections;namespace MailSendOfRecive /命名空間public partial class Form2 : Form /定義類public TcpClient Server; /定義服務器public NetworkStream NetStrm;public StreamReader RdStrm;public string Data,UsName,Pawd,InEmai;publ

27、ic byte szData,other;public List<MailInfo> EMail = new List<MailInfo>(); /鏈表類public List<MailInfo> DMail = new List<MailInfo>();public List<MailInfo> SndMail = new List<MailInfo>();public string CRLF = "rn"public FileStream fs;public int InfoID,BackId;pu

28、blic int DeleTxt = -1; /聲明寫入流DataTable dt = new DataTable(); /數(shù)據(jù)表了，類似于數(shù)據(jù)庫，可以存放數(shù)據(jù)public Form2(string Uname,string Pwd,string IEM)InfoID = -1;InEmai = IEM;/"pop."+IEM;UsName = Uname;Pawd = Pwd;InitializeComponent(); /初始化Inint(); /為網(wǎng)格添加標題dt.Columns.Add("ID", typeof(int);dt.Columns.A

29、dd("主題", typeof(string);dt.Columns.Add("發(fā)件人", typeof(string); /創(chuàng)建對象dt.Columns.Add("時間", typeof(string);dt.Columns.Add("含有附件", typeof(Boolean); private void Inint() /初始化節(jié)點 TreeNode Node = treeView1.Nodes.Add("Name", "郵件歸檔系統(tǒng)");Node.Nodes.Add(

30、"Send", "發(fā)件箱");Node.Nodes.Add("Recove", "收件箱");Node.Nodes.Add("GuiDang", "郵件歸檔"); /獲取對象的集合Node.Nodes.Add("HuiShou", "回收站");private void ShowInfo()private void buttonCon_Click(object sender, EventArgs e) /定義點擊事件Server = n

31、ew TcpClient("pop."+InEmai, 110); /初始化服務器tryNetStrm = Server.GetStream();RdStrm = new StreamReader(NetStrm,System.Text.Encoding.Default);listBoxStatus.Items.Add(RdStrm.ReadLine(); /向列表添加項Data = "USER " + UsName + CRLF;/textBoxUser.Text+CRLF;szData = System.Text.Encoding.Default.G

32、etBytes(Data); /獲取編碼NetStrm.Write(szData,0,szData.Length);listBoxStatus.Items.Add(RdStrm.ReadLine();Data = "PASS " + Pawd + CRLF;/textBoxPwd.Text+CRLF;szData = System.Text.Encoding.Default.GetBytes(Data); /獲取編碼NetStrm.Write(szData,0,szData.Length);listBoxStatus.Items.Add(RdStrm.ReadLine();

33、 /獲取所有的郵件的大小Data = "STAT " + CRLF;szData = System.Text.Encoding.Default.GetBytes(Data); /獲取編碼NetStrm.Write(szData,0,szData.Length); /寫入數(shù)據(jù)string st = RdStrm.ReadLine();MessageBox.Show(st); /顯示消息框listBoxStatus.Items.Add(st);st = st.Substring(4, 2); /檢索字符串MessageBox.Show(st);int Cout = Int32.

34、Parse(st);if (Cout>0)buttonDel.Enabled = true; /設置控件屬性for (int i = 0; i < Cout;i+ )MailInfo ou = new MailInfo();GetInfo(i+1,ref ou);EMail.Add(ou); /對象添加到結(jié)尾ShowInfo();else buttonDel.Enabled = false; /控件設為不可用buttonCon.Enabled = false; /控件設為不可用buttonDison.Enabled = true;GuiButton.Enabled = true;b

35、uttonDel.Enabled = true; /控件設為不可用treeView1.Enabled = true;catch (System.Exception ex)MessageBox.Show(ex.ToString(); /顯示消息框/按ID讀取郵件并進行解析private void GetInfo(int ID,ref MailInfo NewInfo)richTexOfInfo.AppendText("rn-rn");/追加文本NewInfo.id = ID;string szTemp;trystring st = Convert.ToString(ID);D

36、ata = "UIDL " + st + CRLF; /獲取每個郵件的唯一標示szData = System.Text.Encoding.Default.GetBytes(Data);NetStrm.Write(szData, 0, szData.Length); /寫入數(shù)據(jù)szTemp = RdStrm.ReadLine();richTexOfInfo.AppendText(szTemp + CRLF); /追加文本Data = "RETR " + st + CRLF;szData = System.Text.Encoding.Default.GetB

37、ytes(Data); /獲取編碼NetStrm.Write(szData, 0, szData.Length);szTemp = RdStrm.ReadLine(); /讀取字符串并返回richTexOfInfo.AppendText(szTemp + CRLF);szTemp = RdStrm.ReadLine();elsecatch (System.Exception ex)listBoxStatus.Items.Add("Error:" + ex.ToString();private void buttonDison_Click(object sender, Eve

38、ntArgs e) /退出連接Data = "QUIT "+CRLF;szData = System.Text.Encoding.ASCII.GetBytes(Data); /獲取編碼NetStrm.Write(szData, 0, szData.Length);NetStrm.Close(); /釋放資源RdStrm.Close();buttonDel.Enabled = false; /設置控件屬性buttonCon.Enabled = true;buttonDison.Enabled = false;public bool tryTran(ref string a)

39、/安照Base64進行解析流文件trybyte outputb = Convert.FromBase64String(a);a = Encoding.Default.GetString(outputb);return true;catch (System.Exception ex) /錯誤信息return false; private void GetString(ref string a,int s,int e) /字符串處理string u1 = "", u2 ="",u3="" /初始化int sum;sum = a.Index

40、Of("B?"); u1 = a.Substring(0, s);u2 = a.Substring(sum+2, e-sum-2);byte outputb = Convert.FromBase64String(u2);u2 = Encoding.Default.GetString(outputb);u3 = a.Substring(e + 2, a.Length - e - 2);a = u1 + u2 + u3;private void buttonRead_Click(object sender, EventArgs e) /定義事件private void butt

41、onDel_Click(object sender, EventArgs e) /刪除郵件tryif (InfoID>-1)string st = InfoID.ToString();dt.Rows.Remove(dt.RowsDeleTxt);dataGridView1.DataSource = dt;richTexOfInfo.Text = ""MessageBox.Show("刪除操作成功", "操作成功"); /顯示信息catch (System.Exception ex) /顯示錯誤MessageBox.Show(ex

42、.Message); /顯示信息private void treeView1_AfterSelect(object sender, TreeViewEventArgs e) /選擇點擊樹節(jié)點時觸發(fā)的事件dt.Clear();richTexOfInfo.Text = SndMailConvert.ToInt32(e.Node.Name).NeiRong;if (dt.Rows.Count>0)this.dataGridView1.DataSource = dt; /獲取數(shù)據(jù)源else private void GuiButton_Click(object sender, EventArgs

43、 e) /進行歸檔treeView1.Nodes"Name".Nodes"GuiDang".Nodes.Add("ShiYang", "實驗報告"); /獲取樹節(jié)點集合treeView1.Nodes"Name".Nodes"GuiDang".Nodes.Add("Other","其他郵件");foreach (MailInfo a in EMail)if (a.Ttile.IndexOf("實驗報告")> 0)

44、treeView1.Nodes"Name".Nodes"GuiDang".Nodes"ShiYang".Nodes.Add(a.sender, a.sender); /獲取樹節(jié)點集合else treeView1.Nodes"Name".Nodes"GuiDang".Nodes"Other".Nodes.Add(a.sender, a.sender);GuiButton.Enabled = false; /控件設為不可用private void dataGridView1_Ro

45、wHeaderMouseClick(object sender, DataGridViewCellMouseEventArgs e) /點擊表格時觸發(fā)的事件DeleTxt = e.RowIndex; /獲取索引InfoID = (int)this.dataGridView10, e.RowIndex.Value; /獲取值foreach (MailInfo a in EMail)if (a.id = InfoID)richTexOfInfo.Text = a.NeiRong; /獲取文本break;public void GetSenMail(List<MailInfo> e) /

46、獲取發(fā)件模塊送的數(shù)據(jù)if (e.Count>0)foreach (MailInfo a in e)int i = treeView1.Nodes"Name".Nodes"Send".Nodes.Count;treeView1.Nodes"Name".Nodes"Send".Nodes.Add(i.ToString(),a.geter);SndMail.Add(a); /添加對象到結(jié)尾處private void button1_Click(object sender, EventArgs e) /跳到發(fā)件界面F

47、orm1 Se = new Form1(this, UsName, Pawd, InEmai);this.Hide();Se.Show();private void Form2_FormClosed(object sender, FormClosedEventArgs e) /程序退出處理Application.Exit(); /停止程序private void button2_Click(object sender, EventArgs e) /還原回收站中的數(shù)據(jù)treeView1.Nodes"Name".Nodes"HuiShou".Nodes.Re

48、move(treeView1.Nodes"Name".Nodes"HuiShou".NodesBackId.ToString(); /獲取集合foreach (MailInfo a in DMail)if (a.id = BackId)dt.Rows.Add(new Object a.id, a.Ttile, a.sender, a.Datatime, a.Fujian ); /獲取集合dataGridView1.DataSource = dt; /獲取數(shù)據(jù)源private void Form2_Load(object sender, EventArgs e)public class MailInfo public int id;public string sender; /寄件人public string geter; /收件人public Boolean Fujian; /是否有附件public string FJname; /附件名稱public string Ttile; public string NeiRong; /內(nèi)容public string Datatime; /日期pu