电子邮件客户端程序设计与实现

今天是课程设计的第二天，这次课程设计我只打算做五个实验，这是第二个。

首先要配置测试使用的QQ邮箱，不然会出现服务器响应为:Error: need EHLO and AUTH first !”问题。

配置qq邮箱的步骤及填写授权码

1、首先在QQ邮箱当中开启“POP3/SMTP服务”

2、开启后点击下方生成授权码

3、使用base64加密账号与密码

4、使用base64加密后的授权码替代登陆密码，如下图所示：

5.尝试调试程序

设计结果及结果分析

查看邮件：

发送邮件：

#include <iostream>
#include <string>
#include <WinSock2.h>
#include <stdio.h>
#include <unistd.h>

using namespace std;
#pragma comment(lib, "ws2_32.lib") /*链接ws2_32.lib动态链接库*/

void mail(){
char buff[50000]; //收到recv函数返回的结果
    string message;
    string info;
    string subject;
    WSADATA wsaData;
    WORD wVersionRequested = MAKEWORD(2, 1);
    //WSAStarup，即WSA(Windows SocKNDs Asynchronous，Windows套接字异步)的启动命令
    int err = WSAStartup(wVersionRequested, &wsaData);
    SOCKADDR_IN addrServer; //服务端地址
    HOSTENT *pHostent;//hostent是host entry的缩写，该结构记录主机的信息，包括主机名、别名、地址类型、地址长度和地址列表
    SOCKET sockClient; //客户端的套接字
    /*
    使用 MAIL 命令指定发送者
    使用 RCPT 命令指定接收者，可以重复使用RCPT指定多个接收者
    */
    cout << "你想查看邮件还是发邮件？\n\t1.查看邮箱\n\t2.发送邮件\n";
    int call;
    cin >> call;
    if (call == 2)
    {
        sockClient = socket(AF_INET, SOCK_STREAM, 0); //建立socket对象
        pHostent = gethostbyname("smtp.qq.com");      //得到有关于域名的信息,链接到qq邮箱服务器
        addrServer.sin_addr.S_un.S_addr = *((DWORD *) pHostent->h_addr_list[0]); //得到smtp服务器的网络字节序的ip地址
        addrServer.sin_family = AF_INET;
        addrServer.sin_port = htons(25);      //连接端口25
        //int connect (SOCKET s , const struct sockaddr FAR *name , int namelen ); //函数原型
        err = connect(sockClient, (SOCKADDR *) &addrServer, sizeof(SOCKADDR)); //向服务器发送请求
        buff[recv(sockClient, buff, 500, 0)] = '\0';
        /*
        登录邮件服务器
        */
        message = "ehlo qq.com\r\n";
        send(sockClient, message.c_str(), message.length(), 0);      //发送ehlo命令
        buff[recv(sockClient, buff, 500, 0)] = '\0';                  //接收返回值
        // cout <<"1" <<  buff << endl;

message = "auth login\r\n";
        send(sockClient, message.c_str(), message.length(), 0);
        buff[recv(sockClient, buff, 500, 0)] = '\0';
        // cout <<"2" <<  buff << endl;
        /*
        发送base64加密的用户名、密码
        */
        message = "MTAyNTE0MjkzMg==\r\n";
        send(sockClient, message.c_str(), message.length(), 0);
        buff[recv(sockClient, buff, 500, 0)] = '\0';
        // cout <<"3" <<  buff << endl;

message = "bXhkeXd1ZnVhcHVnYmVlag==\r\n";/**/
        send(sockClient, message.c_str(), message.length(), 0);
        buff[recv(sockClient, buff, 500, 0)] = '\0';
        // cout <<"4" <<  buff << endl;

/*
        Author:hyn
        Time:2021.12.28
        */

string mail;
        cout << "请输入收件人邮箱：";
        cin >> mail;
//[email protected]
        message = "MAIL FROM:<[email protected]> \r\nRCPT TO:<";
        message.append(mail);
        message.append("> \r\n");
        send(sockClient, message.c_str(), message.length(), 0);
        buff[recv(sockClient, buff, 500, 0)] = '\0';
        cout <<"5" <<  buff << endl;
        buff[recv(sockClient, buff, 500, 0)] = '\0';
        /*
        使用 DATA 命令告诉服务器要发送邮件内容
        */
        message = "DATA\r\n";
        send(sockClient, message.c_str(), message.length(), 0);
        buff[recv(sockClient, buff, 500, 0)] = '\0';
        // cout <<"6" <<  buff << endl;
        message = "From: [email protected]\r\nTo: " + mail + "\r\nsubject:";
        cout << "主题：";
        cin >> subject;
        message.append(subject);
        message.append("\r\n\r\n");
        cout << "内容：";
        cin >> info;
        message.append(info);
        message.append("\r\n.\r\n");

send(sockClient, message.c_str(), message.length(), 0);
        // cout <<"7" <<  buff << endl;
        message = "QUIT\r\n";
        send(sockClient, message.c_str(), message.length(), 0);
        buff[recv(sockClient, buff, 500, 0)] = '\0';
        // cout <<"8" <<  buff << endl;

cout << "发送成功！" << endl;
        //system("pause");
    }
    if (call == 1)
    {
        sockClient = socket(AF_INET, SOCK_STREAM, 0); //建立socket对象
        const char *host_id = "pop3.126.com";
        pHostent = gethostbyname("pop.qq.com");
        int port = 110;
        addrServer.sin_addr.S_un.S_addr = *((DWORD *) pHostent->h_addr_list[0]); //得到smtp服务器的网络字节序的ip地址
        addrServer.sin_family = AF_INET;
        addrServer.sin_port = htons(port); //连接端口110
        err = connect(sockClient, (SOCKADDR *) &addrServer, sizeof(SOCKADDR)); //向服务器发送请求
        buff[recv(sockClient, buff, 500, 0)] = '\0';

message = "user [email protected]\r\n";
        send(sockClient, message.c_str(), message.length(), 0); //发送账号
        buff[recv(sockClient, buff, 500, 0)] = '\0';   //接收返回值
        // std::cout << "Client : send name \nServer:"
        //         << buff << std::endl;

message = "pass mxdywufuapugbeej\r\n";
        send(sockClient, message.c_str(), message.length(), 0);      //发送授权码
        buff[recv(sockClient, buff, 500, 0)] = '\0';                 //接收返回值
        //std::cout << "Client : send pass \nServer:"
        //          << buff << std::endl;

message = "stat\r\n";
        send(sockClient, message.c_str(), message.length(), 0);      //发送状态
        buff[recv(sockClient, buff, 500, 0)] = '\0';                 //接收返回值
//        sleep(1);
        //std::cout << "Client : send stat \nServer : "
        //       << buff << std::endl;

message = "list\r\n";
        send(sockClient, message.c_str(), message.length(), 0); //发送状态
        buff[recv(sockClient, buff, 50000, 0)] = '\0';   //接收返回值
//        sleep(1);
        cout << "Client : send list \nServer :"
                  << buff << endl;
        while(1)
        {
            int n,option;
            cout << "你先想查看那一封邮件？输入序号"
                      << endl;
            cin >> n;
            message = "retr " + to_string(n) + "\r\n";

send(sockClient, message.c_str(), message.length(), 0); //发送状态
//        sleep(1);
            cout << "Client : send retr (...) \n";

buff[recv(sockClient, buff, 50000, 0)] = '\0';   //接收返回值
            cout << "Server ：" << buff << endl;

cout<<"1.继续查看 2.退出";
            cin>>option;
            if(option == 1)
                ;
            else
                break;
        }
    }
}

int main()
{
    while(1){
        mail();
    }
}