我正在开发一个 C++ 项目，其中包括将信息作为“电子邮件附件”发送给某人的功能。

除了这个“电子邮件”之外，一切都已完成。我不知道如何使这个程序能够发送电子邮件不使用任何电子邮件客户端或打开浏览器。我在互联网上搜索了很多，但找不到任何可用的东西(我对 socket、Winsock 等一无所知)。

最佳答案

我不确定我是否同意你在监视用户所做的事情方面所做的事情，但无论如何这里有一些对发送电子邮件有用的 C++ 代码:

#define WIN32_LEAN_AND_MEAN

#include <stdio.h>
#include <stdlib.h>
#include <fstream.h>
#include <iostream.h>
#include <windows.h>
#include <winsock2.h>

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

// Insist on at least Winsock v1.1
const VERSION_MAJOR = 1;
const VERSION_MINOR = 1;

#define CRLF "\r\n"                 // carriage-return/line feed pair

void ShowUsage(void)
{
  cout << "Usage: SENDMAIL mailserv to_addr from_addr messagefile" << endl
       << "Example: SENDMAIL smtp.myisp.com rcvr@elsewhere.com my_id@mydomain.com message.txt" << endl;

  exit(1);
}

// Basic error checking for send() and recv() functions
void Check(int iStatus, char *szFunction)
{
  if((iStatus != SOCKET_ERROR) && (iStatus))
    return;

  cerr << "Error during call to " << szFunction << ": " << iStatus << " - " << GetLastError() << endl;
}

int main(int argc, char *argv[])
{
  int         iProtocolPort        = 0;
  char        szSmtpServerName[64] = "";
  char        szToAddr[64]         = "";
  char        szFromAddr[64]       = "";
  char        szBuffer[4096]       = "";
  char        szLine[255]          = "";
  char        szMsgLine[255]       = "";
  SOCKET      hServer;
  WSADATA     WSData;
  LPHOSTENT   lpHostEntry;
  LPSERVENT   lpServEntry;
  SOCKADDR_IN SockAddr;

  // Check for four command-line args
  if(argc != 5)
    ShowUsage();

  // Load command-line args
  lstrcpy(szSmtpServerName, argv[1]);
  lstrcpy(szToAddr, argv[2]);
  lstrcpy(szFromAddr, argv[3]);

  // Create input stream for reading email message file
  ifstream MsgFile(argv[4]);

  // Attempt to intialize WinSock (1.1 or later)
  if(WSAStartup(MAKEWORD(VERSION_MAJOR, VERSION_MINOR), &WSData))
  {
    cout << "Cannot find Winsock v" << VERSION_MAJOR << "." << VERSION_MINOR << " or later!" << endl;

    return 1;
  }

  // Lookup email server's IP address.
  lpHostEntry = gethostbyname(szSmtpServerName);
  if(!lpHostEntry)
  {
    cout << "Cannot find SMTP mail server " << szSmtpServerName << endl;

    return 1;
  }

  // Create a TCP/IP socket, no specific protocol
  hServer = socket(PF_INET, SOCK_STREAM, 0);
  if(hServer == INVALID_SOCKET)
  {
    cout << "Cannot open mail server socket" << endl;

    return 1;
  }

  // Get the mail service port
  lpServEntry = getservbyname("mail", 0);

  // Use the SMTP default port if no other port is specified
  if(!lpServEntry)
    iProtocolPort = htons(IPPORT_SMTP);
  else
    iProtocolPort = lpServEntry->s_port;

  // Setup a Socket Address structure
  SockAddr.sin_family = AF_INET;
  SockAddr.sin_port   = iProtocolPort;
  SockAddr.sin_addr   = *((LPIN_ADDR)*lpHostEntry->h_addr_list);

  // Connect the Socket
  if(connect(hServer, (PSOCKADDR) &SockAddr, sizeof(SockAddr)))
  {
    cout << "Error connecting to Server socket" << endl;

    return 1;
  }

  // Receive initial response from SMTP server
  Check(recv(hServer, szBuffer, sizeof(szBuffer), 0), "recv() Reply");

  // Send HELO server.com
  sprintf(szMsgLine, "HELO %s%s", szSmtpServerName, CRLF);
  Check(send(hServer, szMsgLine, strlen(szMsgLine), 0), "send() HELO");
  Check(recv(hServer, szBuffer, sizeof(szBuffer), 0), "recv() HELO");

  // Send MAIL FROM: <sender@mydomain.com>
  sprintf(szMsgLine, "MAIL FROM:<%s>%s", szFromAddr, CRLF);
  Check(send(hServer, szMsgLine, strlen(szMsgLine), 0), "send() MAIL FROM");
  Check(recv(hServer, szBuffer, sizeof(szBuffer), 0), "recv() MAIL FROM");

  // Send RCPT TO: <receiver@domain.com>
  sprintf(szMsgLine, "RCPT TO:<%s>%s", szToAddr, CRLF);
  Check(send(hServer, szMsgLine, strlen(szMsgLine), 0), "send() RCPT TO");
  Check(recv(hServer, szBuffer, sizeof(szBuffer), 0), "recv() RCPT TO");

  // Send DATA
  sprintf(szMsgLine, "DATA%s", CRLF);
  Check(send(hServer, szMsgLine, strlen(szMsgLine), 0), "send() DATA");
  Check(recv(hServer, szBuffer, sizeof(szBuffer), 0), "recv() DATA");

  // Send all lines of message body (using supplied text file)
  MsgFile.getline(szLine, sizeof(szLine));             // Get first line

  do         // for each line of message text...
  {
    sprintf(szMsgLine, "%s%s", szLine, CRLF);
    Check(send(hServer, szMsgLine, strlen(szMsgLine), 0), "send() message-line");
    MsgFile.getline(szLine, sizeof(szLine)); // get next line.
  } while(MsgFile.good());

  // Send blank line and a period
  sprintf(szMsgLine, "%s.%s", CRLF, CRLF);
  Check(send(hServer, szMsgLine, strlen(szMsgLine), 0), "send() end-message");
  Check(recv(hServer, szBuffer, sizeof(szBuffer), 0), "recv() end-message");

  // Send QUIT
  sprintf(szMsgLine, "QUIT%s", CRLF);
  Check(send(hServer, szMsgLine, strlen(szMsgLine), 0), "send() QUIT");
  Check(recv(hServer, szBuffer, sizeof(szBuffer), 0), "recv() QUIT");

  // Report message has been sent
  cout << "Sent " << argv[4] << " as email message to " << szToAddr << endl;

  // Close server socket and prepare to exit.
  closesocket(hServer);

  WSACleanup();

  return 0;
}

互联网上有很多类似问题的链接，我发现了这个:

http://social.msdn.microsoft.com/Forums/en-US/vclanguage/thread/12345906-8a17-41c2-846f-fd3e1a135238/

关于c++ - 用 C++ 发送带有附件的电子邮件，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/7298762/