（1）建立TCP连接
（2）客户端发送HELO命令以标识发件人的身份，服务器以OK作为响应，表明准备接收
memset(buf, 0, 1500);
sprintf(buf, "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;
（3）使用AUTH命令登录SMTP服务器，输入用户名和密码（用户名和密码要用base64进行加密）
memset(buf, 0, 1500);
sprintf(buf, "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;
memset(buf, 0, 1500);
sprintf(buf, username);//user
memset(login, 0, 128);
EncodeBase64(login, buf, strlen(buf));
sprintf(buf, "%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;
sprintf(buf, password);//password
memset(pass, 0, 128);
EncodeBase64(pass, buf, strlen(buf));
sprintf(buf, "%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;
（4）客户端发送MAIL命令输入发件人邮箱地址，服务器以OK作为响应
memset(buf, 0, 1500);
sprintf(buf, "MAIL FROM: <%s>\r\n", username);
send(sockfd, buf, strlen(buf), 0);
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout << "set Mail From Receive: " << rbuf << endl;
（5）客户端发送RCPT命令，标识该电子邮件的计划接收人，服务器以OK作为响应
sprintf(buf, "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;
（6）协商结束后，使用DATA命令发送
sprintf(buf, "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;
（7）以"."号表示结束，输入内容一起发送出去
sprintf(buf, "%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;
（8）结束此次发送，用QUIT命令退出
sprintf(buf, "QUIT\r\n");
send(sockfd, buf, strlen(buf), 0);
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout << "Quit Receive: " << rbuf << endl;
完整Code:
#define _CRT_SECURE_NO_WARNINGS
#include
#include
#include
#include
#pragma comment(lib,"ws2_32")
using namespace std;
struct Base64Date6
{
unsigned int d4 : 6;
unsigned int d3 : 6;
unsigned int d2 : 6;
unsigned int d1 : 6;
};
// 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, char*body, char* hostname, short port, char *username, char *password);
int OpenSocket(struct sockaddr *addr);
int main(int argc, char *argv[])
{
char *EmailTo = argv[1];
char *host = argv[2];
char *port = argv[3];
char *user = argv[4];
char *pass = argv[5];
char *subject = argv[6];
char *filename = argv[7];
char *EmailContents = new char[20000];
char *From = new char[128];
sprintf(From, "From: <%s>\r\n", user);
char *To = new char[128];
sprintf(To, "To: <%s>\r\n", EmailTo);
char *sub = new char[128];
sprintf(sub, "Subject: %s\r\n\r", subject);
short porttemp = 0;
for (int i = 0; i < strlen(port); i++)
{
porttemp = porttemp * 10 + port[i] - '0';
}
FILE *fp;
fp = fopen(filename, "rb");
if (!fp)
{
printf("File path error\n");
return false;
}
//打开传送内容的文件夹并读取到缓冲区
fseek(fp, 0L, SEEK_END);
int fileSize = ftell(fp);
fseek(fp, 0L, SEEK_SET);
cout << fileSize << endl;
char *content = (char*)malloc(sizeof(char) * fileSize);
fread(content, 1, fileSize, fp);
cout << content << endl;
fclose(fp);
sprintf(EmailContents, "%s%s%s%s", From, To, sub, content);
cout << EmailContents << endl;
SendMail(EmailTo, EmailContents, host, porttemp, user, pass);
system("PAUSE");
return 0;
}
// 发送邮件
void SendMail(char*email, char*body, char* hostname, short port, char *username, char *password)
{
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(port);
hostent*hptr = gethostbyname(hostname);
memcpy(&their_addr.sin_addr.S_un.S_addr, hptr->h_addr_list[0], hptr->h_length);
printf("IP of %s is : %d:%d:%d:%d\n",
hostname,
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);
// 连接邮箱服务器，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(buf, "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(buf, "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(buf, username);//user
memset(login, 0, 128);
EncodeBase64(login, buf, strlen(buf));
sprintf(buf, "%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(buf, password);//password
memset(pass, 0, 128);
EncodeBase64(pass, buf, strlen(buf));
sprintf(buf, "%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(buf, "MAIL FROM: <%s>\r\n", username);
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(buf, "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(buf, "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(buf, "%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(buf, "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;
}
// 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(buf, 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;
}
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 '/';
}
用法：SMTP.exe [email protected] smtp.163.com 25 [email protected] password subject test.txt