Thread: e-mail with c/c++

Hi. All I need real quick is a short example on how to e-mail a message to somebody. For example, you have a variable char string[50]. How do you e-mail that to some address?

is it supported on everyones computer so friends can use it?

Winsock is supported on *all modern versions of Windows, yes.

heres my code but i get errors:

Code:

#include <stdio.h>
#include <io.h>

#include <stdio.h>

//#define LINUX /* define this if you are on linux   */
//#define WIN32 /* define this if you are on windows */

#ifdef WIN32
#       include "io.h"
#       include "winsock2.h"      /* WSAGetLastError, WSAStartUp  */
#       define snprintf _snprintf
#endif

#ifdef LINUX
#       include <netdb.h>         /* gethostbyname  */
#       include <netinet/in.h>    /* htons          */
#       include <sys/socket.h>
#endif

static void sendmail_write(const int  sock,const char *str,const char *arg) 
{
    char buf[4096];

    if (arg != NULL)
        snprintf(buf, sizeof(buf), str, arg);        
    else
        snprintf(buf, sizeof(buf), str);
    
    send(sock, buf, strlen(buf), 0);    
}

static int sendmail(const char *from,const char *to,const char *subject,const char *body, const char *hostname,const int   port)
{
    struct hostent *host;   
    struct sockaddr_in saddr_in;
    int sock = 0;

#ifdef WIN32
	WSADATA wsaData;
	if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) 
	{
		return -1;
	}
#endif

    sock = socket(AF_INET, SOCK_STREAM, 0);
	host = gethostbyname(hostname);
	
	saddr_in.sin_family      = AF_INET;
	saddr_in.sin_port        = htons((u_short)port);
	saddr_in.sin_addr.s_addr = 0;

	memcpy((char*)&(saddr_in.sin_addr), host->h_addr, host->h_length);

	if (connect(sock, (struct sockaddr*)&saddr_in, sizeof(saddr_in)) == -1)
	{
		return -2;
	}
    
    sendmail_write(sock, "HELO %s\n",       from);    // greeting
    sendmail_write(sock, "MAIL FROM: %s\n", from);    // from
    sendmail_write(sock, "RCPT TO: %s\n",   to);      // to
    sendmail_write(sock, "DATA\n",          NULL);    // begin data

    // next comes mail headers
    sendmail_write(sock, "From: %s\n",      from);
    sendmail_write(sock, "To: %s\n",        to);
    sendmail_write(sock, "Subject: %s\n",   subject);

    sendmail_write(sock, "\n",              NULL);

    sendmail_write(sock, "%s\n",            body);    // data

    sendmail_write(sock, ".\n",             NULL);    // end data
    sendmail_write(sock, "QUIT\n",          NULL);    // terminate

    close(sock);

    return 0;
}


int main(int argc, char *argv[]) {
    
    int ret = sendmail(
        "[email protected]",   /* from     */
        "[email protected]",       /* to       */
        "Subject",              /* subject  */
        "body",                 /* body     */
        "mx1.hotmail.com",             /* hostname */
        25                      /* port     */
    );

    if (ret != 0)
        fprintf(stderr, "Failed to send mail (code: %i).\n", ret);
    else
        fprintf(stdout, "Mail successfully sent.\n");

    return ret;
}

--------------------Configuration: email - Win32 Debug--------------------
Linking...
main.obj : error LNK2001: unresolved external symbol __imp__connect@12
main.obj : error LNK2001: unresolved external symbol __imp__htons@4
main.obj : error LNK2001: unresolved external symbol __imp__gethostbyname@4
main.obj : error LNK2001: unresolved external symbol __imp__socket@12
main.obj : error LNK2001: unresolved external symbol __imp__WSAStartup@8
main.obj : error LNK2001: unresolved external symbol __imp__send@16
LIBCD.lib(wincrt0.obj) : error LNK2001: unresolved external symbol _WinMain@16
Debug/email.exe : fatal error LNK1120: 7 unresolved externals
Error executing link.exe.

email.exe - 8 error(s), 0 warning(s)

whats wrong?

did you link to wsock32.lib??

if you are using microsoft visual c ++ do the following

under the "project" menu choose settings or press Alt+F7

choose the link tab

under "object/library modules" add wsock32.lib

i did it for console (even tried again), but still get thta winmain error. winmain is nowhere in my code. other than that it works now. hmm...

k i got it to run but i don't get the email...

Ok, here's an example I found on google, with 1 error:

Code:

#include <comdef.h>
#include <iostream>
#include "ansmtp.tlh"
using namespace ANSMTPLib;
using namespace std;

void SendEmail()
{
  ::CoInitialize( NULL );
  IOBJPtr oSmtp = NULL;
  oSmtp.CreateInstance("ANSMTP.OBJ");
	
  oSmtp->ServerAddr = _bstr_t( "mail.adminsystem.net" );
  oSmtp->FromAddr = _bstr_t( "[email protected]" );
  oSmtp->AddRecipient( _bstr_t("Support Team"), 
                      _bstr_t("[email protected]"), 0 );

  oSmtp->Subject = _bstr_t("Test");
  oSmtp->BodyText = _bstr_t("Hello, this is a test....");
  
  if( oSmtp->SendMail() == 0 )
    cout << "Message delivered!" << endl;
  else
    cout << (const char*)(oSmtp->GetLastErrDescription()) << endl;
}

int main(int argc, char* argv[])
{
  SendEmail();
  return 0;
}

testmailertest\main.cpp(32) : fatal error C1010: unexpected end of file while looking for precompiled header directive

oh, and the other one doesn't actually send the mail....

Originally posted by deltabird
Ok, here's an example I found on google, with 1 error:

Code:

#include <comdef.h>
#include <iostream>
#include "ansmtp.tlh"
using namespace ANSMTPLib;
using namespace std;

void SendEmail()
{
  ::CoInitialize( NULL );
  IOBJPtr oSmtp = NULL;
  oSmtp.CreateInstance("ANSMTP.OBJ");
	
  oSmtp->ServerAddr = _bstr_t( "mail.adminsystem.net" );
  oSmtp->FromAddr = _bstr_t( "[email protected]" );
  oSmtp->AddRecipient( _bstr_t("Support Team"), 
                      _bstr_t("[email protected]"), 0 );

  oSmtp->Subject = _bstr_t("Test");
  oSmtp->BodyText = _bstr_t("Hello, this is a test....");
  
  if( oSmtp->SendMail() == 0 )
    cout << "Message delivered!" << endl;
  else
    cout << (const char*)(oSmtp->GetLastErrDescription()) << endl;
}

int main(int argc, char* argv[])
{
  SendEmail();
  return 0;
}

testmailertest\main.cpp(32) : fatal error C1010: unexpected end of file while looking for precompiled header directive

Easy solution to this problem, and your other unresolved external WinMain.

To fix the precompiled header error go:
Project->Settings->C/C++->Category: Precompiled Headers and select "Not using precompiled headers"

To fix the linker error:
Project->Settings->Link
In the Project Options textbox, scroll down until you see /subsystem:#######, where ####### is either "console" or "windows". Remove this line.

These should really be in the FAQ...

Alright, well it's still not sending for some reason. It stops when it says "354 Please start mail input" and there ARE lines after that that it sould write. Here's the code:

Code:

#include <stdio.h>
#include <io.h>\

int  rc;
    char buf[256];

//#define LINUX /* define this if you are on linux   */
//#define WIN32 /* define this if you are on windows */

#ifdef WIN32
#       include "io.h"
#       include "winsock2.h"      /* WSAGetLastError, WSAStartUp  */
#       define snprintf _snprintf
#endif

#ifdef LINUX
#       include <netdb.h>         /* gethostbyname  */
#       include <netinet/in.h>    /* htons          */
#       include <sys/socket.h>
#endif

#pragma comment(lib, "wsock32.lib")

static void sendmail_write(const int  sock,const char *str,const char *arg) 
{
    char buf[4096];

    if (arg != NULL)
        snprintf(buf, sizeof(buf), str, arg);        
    else
        snprintf(buf, sizeof(buf), str);
    
    send(sock, buf, strlen(buf), 0); 
	
	if ((rc = recv(sock, buf, sizeof(buf) - 1, 0)) == -1) {
    perror("recv");
	} else {
    buf[rc] = 0;
    printf("%s", buf);
	}
}

static int sendmail(const char *from,const char *to,const char *subject,const char *body, const char *hostname,const int   port)
{
    struct hostent *host;   
    struct sockaddr_in saddr_in;
    int sock = 0;

#ifdef WIN32
	WSADATA wsaData;
	if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) 
	{
		return -1;
	}
#endif

    sock = socket(AF_INET, SOCK_STREAM, 0);
	host = gethostbyname(hostname);
	
	saddr_in.sin_family      = AF_INET;
	saddr_in.sin_port        = htons((u_short)port);
	saddr_in.sin_addr.s_addr = 0;

	memcpy((char*)&(saddr_in.sin_addr), host->h_addr, host->h_length);

	if (connect(sock, (struct sockaddr*)&saddr_in, sizeof(saddr_in)) == -1)
	{
		return -2;
	}
    
    sendmail_write(sock, "helo %s\r\n",       from);    // greeting
    sendmail_write(sock, "mail from: %s\r\n", from);    // from
    sendmail_write(sock, "rcpt to: %s\r\n",   to);      // to
    sendmail_write(sock, "data\r\n\n",        NULL);    // begin data

    // next comes mail headers
    sendmail_write(sock, "From: %s\r\n",      from);
    sendmail_write(sock, "To: %s\r\n",        to);
    sendmail_write(sock, "Subject: %s\r\n",   subject);
	sendmail_write(sock, "Date: 6/6/6\r\n", NULL);

    sendmail_write(sock, "\r\n",              NULL);

    sendmail_write(sock, "%s\r\n",            body);    // data

    sendmail_write(sock, ".\r\n",             NULL);    // end data
	//Sleep(5000);
    sendmail_write(sock, "QUIT\r\n",          NULL);    // terminate

    #ifdef WIN32
    closesocket(sock);
    #else
    close(sock);
    #endif

    return 0;
}

int main(int argc, char *argv[]) {

	
    
    int ret = sendmail(
        "[email protected]",   /* from     */
        "[email protected]",       /* to       */
        "Subject",              /* subject  */
        "body",                 /* body     */
        "mx2.hotmail.com",             /* hostname */
        25                      /* port     */
    );

    if (ret != 0)
        fprintf(stderr, "Failed to send mail (code: %i).\n", ret);
    else
        fprintf(stdout, "Mail successfully sent.\n");

    return ret;
}