C++发送邮件实现

// SendMail.h
#ifndef _SEND_MAIL_H_
#define _SEND_MAIL_H_

#include <windows.h>
#include <stdio.h>
#include <WinSock.h>
#include <iostream>
using namespace std;

// 协议中加密部分使用的是base64方法
char ConvertToBase64(char c6);
void EncodeBase64(char *dbuf, char *buf128, int len);
void SendMail(char *email, const char *body);
int  OpenSocket(struct sockaddr *addr);

#endif

// SendMail.cpp

#include "SendMail.h"

#pragma  comment(lib, "ws2_32.lib")

struct Base64Date6
{
unsigned int d4 : 6;
unsigned int d3 : 6;
unsigned int d2 : 6;
unsigned int d1 : 6;
};

char ConvertToBase64(char uc)
{
if (uc < 26)
{
return 'A' + uc;
}
if (uc < 52)
{
return 'a' + (uc - 26);
}
if (uc < 62)
{
return '0' + (uc - 52);
}
if (uc == 62)
{
return '+';
}
return '/';
}

// base64的实现
void EncodeBase64(char *dbuf, char *buf128, int len)
{
struct Base64Date6 *ddd = NULL;
int           i = 0;
char          buf[256] = { 0 };
char          *tmp = NULL;
char          cc = '\0';

memset(buf, 0, 256);
strcpy_s(buf, 256, buf128);
for (i = 1; i <= len / 3; i++)
{
tmp = buf + (i - 1) * 3;
cc = tmp[2];
tmp[2] = tmp[0];
tmp[0] = cc;
ddd = (struct Base64Date6 *)tmp;
dbuf[(i - 1) * 4 + 0] = ConvertToBase64((unsigned int)ddd->d1);
dbuf[(i - 1) * 4 + 1] = ConvertToBase64((unsigned int)ddd->d2);
dbuf[(i - 1) * 4 + 2] = ConvertToBase64((unsigned int)ddd->d3);
dbuf[(i - 1) * 4 + 3] = ConvertToBase64((unsigned int)ddd->d4);
}
if (len % 3 == 1)
{
tmp = buf + (i - 1) * 3;
cc = tmp[2];
tmp[2] = tmp[0];
tmp[0] = cc;
ddd = (struct Base64Date6 *)tmp;
dbuf[(i - 1) * 4 + 0] = ConvertToBase64((unsigned int)ddd->d1);
dbuf[(i - 1) * 4 + 1] = ConvertToBase64((unsigned int)ddd->d2);
dbuf[(i - 1) * 4 + 2] = '=';
dbuf[(i - 1) * 4 + 3] = '=';
}
if (len % 3 == 2)
{
tmp = buf + (i - 1) * 3;
cc = tmp[2];
tmp[2] = tmp[0];
tmp[0] = cc;
ddd = (struct Base64Date6 *)tmp;
dbuf[(i - 1) * 4 + 0] = ConvertToBase64((unsigned int)ddd->d1);
dbuf[(i - 1) * 4 + 1] = ConvertToBase64((unsigned int)ddd->d2);
dbuf[(i - 1) * 4 + 2] = ConvertToBase64((unsigned int)ddd->d3);
dbuf[(i - 1) * 4 + 3] = '=';
}
return;
}
// 发送邮件
void SendMail(char *email, const char *body)
{
int     sockfd = { 0 };
char    buf[1500] = { 0 };
char    rbuf[1500] = { 0 };
char    login[128] = { 0 };
char    pass[128] = { 0 };
WSADATA WSAData;
struct sockaddr_in their_addr = { 0 };
WSAStartup(MAKEWORD(2, 2), &WSAData);
memset(&their_addr, 0, sizeof(their_addr));

their_addr.sin_family = AF_INET;
their_addr.sin_port = htons(25);    // 一般是25端口不需要改
hostent* hptr = gethostbyname("smtp.126.com");          // 端口和服务器
memcpy(&their_addr.sin_addr.S_un.S_addr, hptr->h_addr_list[0], hptr->h_length);
printf("IP of smpt.163.com is : %d:%d:%d:%d\n",
their_addr.sin_addr.S_un.S_un_b.s_b1,
their_addr.sin_addr.S_un.S_un_b.s_b2,
their_addr.sin_addr.S_un.S_un_b.s_b3,
their_addr.sin_addr.S_un.S_un_b.s_b4);

// 连接邮件服务器，如果连接后没有响应，则2 秒后重新连接
sockfd = OpenSocket((struct sockaddr *)&their_addr);
memset(rbuf, 0, 1500);
while (recv(sockfd, rbuf, 1500, 0) == 0)
{
cout << "reconnect..." << endl;
Sleep(2);
sockfd = OpenSocket((struct sockaddr *)&their_addr);
memset(rbuf, 0, 1500);
}

cout << rbuf << endl;

// EHLO
memset(buf, 0, 1500);
sprintf_s(buf, 1500, "EHLO HYL-PC\r\n");
send(sockfd, buf, strlen(buf), 0);
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout << "EHLO REceive: " << rbuf << endl;

// AUTH LOGIN
memset(buf, 0, 1500);
sprintf_s(buf, 1500, "AUTH LOGIN\r\n");
send(sockfd, buf, strlen(buf), 0);
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout << "Auth Login Receive: " << rbuf << endl;

// USER
memset(buf, 0, 1500);
sprintf_s(buf, 1500, "xxxxxx@126.com");//你的邮箱账号
memset(login, 0, 128);
EncodeBase64(login, buf, strlen(buf));
sprintf_s(buf, 1500, "%s\r\n", login);
send(sockfd, buf, strlen(buf), 0);
cout << "Base64 UserName: " << buf << endl;
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout << "User Login Receive: " << rbuf << endl;

// PASSWORD
sprintf_s(buf, 1500, "********");//你的邮箱密码
memset(pass, 0, 128);
EncodeBase64(pass, buf, strlen(buf));
sprintf_s(buf, 1500, "%s\r\n", pass);
send(sockfd, buf, strlen(buf), 0);
cout << "Base64 Password: " << buf << endl;

memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout << "Send Password Receive: " << rbuf << endl;

// MAIL FROM
memset(buf, 0, 1500);
sprintf_s(buf, 1500, "MAIL FROM: <xxxx@126.com>\r\n");  //此处要和发邮件的邮箱保持一致
send(sockfd, buf, strlen(buf), 0);
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout << "set Mail From Receive: " << rbuf << endl;

// RCPT TO 第一个收件人
sprintf_s(buf, 1500, "RCPT TO:<%s>\r\n", email);
send(sockfd, buf, strlen(buf), 0);
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout << "Tell Sendto Receive: " << rbuf << endl;

// DATA 准备开始发送邮件内容
sprintf_s(buf, 1500, "DATA\r\n");
send(sockfd, buf, strlen(buf), 0);
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout << "Send Mail Prepare Receive: " << rbuf << endl;

// 发送邮件内容，\r\n.\r\n内容结束标记
sprintf_s(buf, 1500, "%s\r\n.\r\n", body);
send(sockfd, buf, strlen(buf), 0);
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout << "Send Mail Receive: " << rbuf << endl;

// QUIT
sprintf_s(buf, 1500, "QUIT\r\n");
send(sockfd, buf, strlen(buf), 0);
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout << "Quit Receive: " << rbuf << endl;

//清理工作
closesocket(sockfd);
WSACleanup();
return;
}
// 打开TCP Socket连接
int OpenSocket(struct sockaddr *addr)
{
int sockfd = 0;
sockfd = socket(PF_INET, SOCK_STREAM, 0);
if (sockfd < 0)
{
cout << "Open sockfd(TCP) error!" << endl;
exit(-1);
}
if (connect(sockfd, addr, sizeof(struct sockaddr)) < 0)
{
cout << "Connect sockfd(TCP) error!" << endl;
exit(-1);
}
return sockfd;
}

// SendMailTest.cpp

#include "SendMail.h"

int main()
{
int num = 100;
string EmailContents = "From: \"lucy\"<xxxx@126.com>\r\n"
+ string("To: \"dasiy\"<yyyy@126.com>\r\n")
+ "Subject: Hello\r\n\r\n"
+ "test sending variable" + to_string(num) + "\n";

char EmailTo[] = "yyyy@126.com";    //此处是送达的邮箱, 需和EmailContents里的保持一致

SendMail(EmailTo, EmailContents.c_str());
return 0;
}