SMTP协议和POP3协议就不详细阐述了 ，网上一搜索会有一大把给你解释的。
下面直接贴代码：
首先写一个class Sock类，这个类的功能主要是创建套接字（即int sock）,用套接字來连接邮箱服务器。类里面还带有send_socket和recv_socket两个函数，其功能分别是向邮箱服务器发送协议指令和接收服务器反馈回来的信息。
sock.h文件
- 1 #ifndef __SOCK_H__
- 2 #define __SOCK_H__
- 3
- 4 #include <iostream>
- 5 #include <sys/socket.h>
- 6 #include <sys/epoll.h>
- 7 #include <stdio.h>
- 8 #include <netinet/in.h>
- 9
- 10 class Sock
- 11 {
- 12 public:
- 13 Sock();
- 14 bool Connect(const char *host_id, const int &port);
- 15 void send_socket(const char *s);
- 16 int recv_socket();
- 17 const char * get_recvbuf();
- 18 ~Sock();
- 19 private:
- 20 char recvbuf[BUFSIZ];
- 21 int sock;
- 22 int num;
- 23 struct sockaddr_in server;
- 24 struct hostent *hp;
- 25 };
- 26
- 27 #endif
sock.cpp文件
- 1 #include "sock.h"
- 2 #include <stdexcept>
- 3 #include <netdb.h>
- 4 #include <string.h>
- 5 #include <sys/types.h>
- 6
- 7 Sock::Sock()
- 8 {
- 9 sock = socket(AF_INET, SOCK_STREAM, 0);
- 10 if(sock == -1)
- 11 {
- 12 throw std::runtime_error("socket init error\n");
- 13 }
- 14 }
- 15 Sock::~Sock()
- 16 {
- 17 close(sock);
- 18 }
- 19 bool Sock::Connect(const char *host_id, const int &port)
- 20 {
- 21 server.sin_family = AF_INET;
- 22 hp = gethostbyname(host_id);
- 23 if(hp == (struct hostent *) 0)
- 24 {
- 25 std::cerr << "服务器地址获取失败！" << std::endl;
- 26 return false;
- 27 }
- 28 memcpy((char *)&server.sin_addr,
- 29 (char *)hp->h_addr, hp->h_length);
- 30 server.sin_port = htons(port);
- 31 if(connect(sock, (sockaddr *) &server, sizeof server) == -1)
- 32 {
- 33 std::cerr << "连接服务器失败！" << std::endl;
- 34 return false;
- 35 }
- 36 else
- 37 return true;
- 38 }
-
- void Sock::send_socket(const char *s)
- 40 {
- 41 send(sock, s, strlen(s), 0);
- 42 }
- 43 int Sock::recv_socket()
- 44 {
- 45 memset(recvbuf, 0,BUFSIZ);
- 46 return recv(sock, recvbuf, BUFSIZ, 0);
- 47 }
- 48 const char * Sock::get_recvbuf()
- 49 {
- 50 return recvbuf;
- 51 }
下面是用SMTP协议发送邮件，格式就如代码所示。了解下SMTP协议，依葫芦画瓢了。
- 1 #include "sock.h"
- 2 #include <iostream>
- 3
- 4 int main()
- 5 {
- 6 Sock sock;
- 7 const char *host_id = "smtp.126.com";
- 8 int port = 25;
- 9 char wkstr[100] = "hello,how are you?";
- 10 if(sock.Connect(host_id, port) == false)
- 11 return 1;
- 12 sock.recv_socket();
- 13 std::cout << "Client : connected! \nServer :"
- 14 << sock.get_recvbuf() << std::endl;
- 15
- 16
- 17 sock.send_socket("EHLO **********\r\n");
- 18 sock.recv_socket();
- 19 std::cout << "Client : send helo \nServer :"
- 20 << sock.get_recvbuf() << std::endl;
- 21
- 22
- 23 sock.send_socket("auth login\r\n");
- 24 sock.recv_socket();
- 25 std::cout << "Client : send auth login \nServer :"
- 26 << sock.get_recvbuf() << std::endl;
- 27
- 28
-
-
- 31 sock.send_socket("**********");
- 32 sock.send_socket("\r\n");
- 33 sock.recv_socket();
- 34 std::cout << "Client : send name \nServer :"
- 35 << sock.get_recvbuf() << std::endl;
-
- 37
- 38 sock.send_socket("base64编码后的密码");
- 39 sock.send_socket("\r\n");
- 40 sock.recv_socket();
- 41 std::cout << "Client : send password \nServer :"
- 42 << sock.get_recvbuf() << std::endl;
- 43
- 44
- 45 sock.send_socket("mail from: <");
- 46 sock.send_socket("yuzhenxiong0823@126.com");
- 47 sock.send_socket(">");
- 48 sock.send_socket("\r\n");
- 49 sock.recv_socket();
- 50 std::cout << "Client: send mail from \nServer :"
- 51 << sock.get_recvbuf() << std::endl;
- 52
- 53
- 54 sock.send_socket("rcpt to: <");
- 55 sock.send_socket("120091241@qq.com");
- 56 sock.send_socket(">");
- 57 sock.send_socket("\r\n");
- 58 sock.recv_socket();
- 59 std::cout << "Client : send rcpt to \nServer"
- 60 << sock.get_recvbuf() << std::endl;
- 61
- 62
- 63 sock.send_socket("data\r\n");
- 64 sock.recv_socket();
- 65 std::cout << "Client : send data \nServer :"
- 66 << sock.get_recvbuf() << std::endl;
- 67
-
- 69 sock.send_socket("subject:");
- 70 sock.send_socket("testmail\r\n");
- 71 sock.send_socket("\r\n\r\n");
- 72 sock.send_socket("hello,how are you.\r\n");
- 73 sock.send_socket(".\r\n");
- 74 sock.recv_socket();
- 75 std::cout << "Client : send content \nServer :"
- 76 << sock.get_recvbuf() << std::endl;
-
- sock.send_socket("quit\r\n");
- 79 sock.recv_socket();
- 80 std::cout << "Client : send quit \nServer :"
- 81 << sock.get_recvbuf() << std::endl;
- 82
- 83 }
