Send Email with C++ WINSOCK (TCP, SSL) - c++

Question

I've been trying for days to send a short, plain-text email to myself with C++. I'm using Visual Studio Express 2015. I'm eventually hoping to email automatic alerts to myself. I am using a Gmail account. I can't seem to manage to get this to work. I can send data, but can't receive. The server is closing my connection with Error 10054. (You can read about what that error means on this page.)
Here is the history: I have cobbled all this together from lots of S.O. posts and MSDN articles. I used to have a functional WSASetSocketSecurity section in this code, but for whatever reason, my connection attempts were timing out, so I omitted it. At this point, I will settle for the server not severing my connection when I send EHLO or HELO.
I'm really at a loss for how to proceed. Days of exploration, dozens of read articles, hundreds of dead ends. I hope that you'll forgive the few bits of junk code and that S.O. removed my hand alignments. Please take a look, let me know what I am doing wrong, let me know of any improper style, or anything else that offends your good-coder sensibilities. Many thanks.
#include "stdafx.h"
#include <exception>
#include <string>
#include <iostream> // In-out stream objects for development
#include <stdio.h> // Standard in-out for development
#include <winsock2.h> // For making socket connection to email server
#include <Mstcpip.h>
#include <Ws2tcpip.h> // Enhanced protocols to assist winsock2.h
#pragma comment(lib, "Ws2_32.lib") // Library for winsock2.h
#pragma comment(lib, "Fwpuclnt.lib") // Library for winsock2.h
#define BUFFER_SIZE 512
using namespace std;
void cleanup(SOCKET ConnectSocket, struct addrinfo *result) {
if (ConnectSocket != INVALID_SOCKET) {
closesocket(ConnectSocket);
}
freeaddrinfo(result);
WSACleanup();
cout << "socket closed" << endl;
cin.get(); // Development only
}
int _tmain(int argc, char* argv[]) {
// Initialize email parameters
char bccAddresses[64] = "";
char fromAddress[64] = "my_email#host.com";
char msg[512] = "Hello world!";
char port[12] = "465";
char serverName[64] = "smtp.host.com";
char toAddresses[64] = "my_email#host.com";
SOCKET ConnectSocket = INVALID_SOCKET;
struct addrinfo *result = NULL;
struct addrinfo *ptr = NULL;
struct addrinfo hints;
WSADATA wsaData;
try {
// Initialize Winsock
int iResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
if (iResult == SOCKET_ERROR) {
cout << "Error " << iResult << endl;
throw std::exception("WSAStartup failed\n");
}
cout << "WSAStartup successful: " << iResult << endl;
// Set up the hints socket address structure
ZeroMemory(&hints, sizeof(hints));
hints.ai_flags = AI_SECURE;
hints.ai_family = AF_INET;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = IPPROTO_TCP;
// Resolve the server address and port
iResult = getaddrinfo(serverName, port, &hints, &result);
if (iResult == SOCKET_ERROR) {
cout << "Error " << WSAGetLastError() << endl;
throw std::exception("getaddrinfo failed\n");
}
cout << "getaddrinfo successful: " << iResult << endl;
// Connect to the socket
ptr = result;
ConnectSocket = WSASocket(ptr->ai_family, ptr->ai_socktype, ptr->ai_protocol, NULL, 0, 0);
if (ConnectSocket == INVALID_SOCKET) {
cout << "Error " << WSAGetLastError() << endl;
throw std::exception("Error at socket\n");
}
cout << "WSASocket successful: " << iResult << endl;
// Connect via the socket
iResult = connect(ConnectSocket, ptr->ai_addr, (int)ptr->ai_addrlen);
if (iResult == SOCKET_ERROR) {
cout << "Error " << WSAGetLastError() << endl;
closesocket(ConnectSocket);
ConnectSocket = INVALID_SOCKET;
throw std::exception("Unable to connect to server!\n");
}
cout << "connect successful: " << iResult << endl;
// Send message
char sendBuffer[BUFFER_SIZE] = "What is your malfunction";
char recvBuffer[BUFFER_SIZE];
sprintf_s(sendBuffer, BUFFER_SIZE, "EHLO %s%s", serverName, "\r\n");
iResult = send(ConnectSocket, sendBuffer, BUFFER_SIZE, 0);
if (iResult == SOCKET_ERROR) {
cout << "Error " << WSAGetLastError() << endl;
throw std::exception("WINSOCK send failed\n");
}
cout << "Sent:\n" << sendBuffer << "Byte count: " << iResult << endl;
iResult = recv(ConnectSocket, recvBuffer, BUFFER_SIZE, 0);
if (iResult == SOCKET_ERROR) {
cout << "Error " << WSAGetLastError() << endl;
throw std::exception("WINSOCK recv failed\n");
}
cout << "EHLO response: " << iResult << endl;
sprintf_s(sendBuffer, BUFFER_SIZE, "QUIT%s", "\r\n");
iResult = send(ConnectSocket, sendBuffer, BUFFER_SIZE, 0);
if (iResult == SOCKET_ERROR) {
cout << "Error " << WSAGetLastError() << endl;
throw std::exception("WINSOCK send failed\n");
}
cout << "Sent:\n" << sendBuffer << "Byte count: " << iResult << endl;
iResult = recv(ConnectSocket, recvBuffer, BUFFER_SIZE, 0);
if (iResult < 0) {
cout << "Error " << WSAGetLastError() << endl;
throw std::exception("WINSOCK recv failed\n");
}
cout << "Quit response: " << iResult << endl;
// Shutdown the connection
iResult = shutdown(ConnectSocket, SD_SEND);
if (iResult == SOCKET_ERROR) {
cout << "Error " << WSAGetLastError() << endl;
throw std::exception("shutdown failed\n");
}
// Clean up
cleanup(ConnectSocket, result);
return 0;
}
catch (std::exception err) {
printf(err.what());
cleanup(ConnectSocket, result);
return 1;
}
catch (...) {
printf("Unknown error\n");
cleanup(ConnectSocket, result);
return 2;
}
}

Answer 1

Three parts to this answer.
MIME Encode the username and password.
ACTUALLY send the username and password! :)
Some servers are skeptical and want you to say HELO or EHLO twice.
I will post full code soon. Although I feel I was about 40% of the way there, I owe my success to this site: http://www.coastrd.com/smtps.