Le protocole SMTP: client smtp en visual c++

#include <winsock.h>
#include <ostream.h>

SOCKET to_server_socket = 0;
char   server_name[]    = "SERVEUR"; // Changer SERVEUR par le nom du serveur
int    port             = 25;



void bcopy( void * source, void * destination, int size )
{
   char * src = ( char * ) source;
   char * dst = ( char * ) destination;

   for( int i=0; i<size; i++ )
      dst[i] = src[i];
}



void bzero( void * destination, int size )
{
   char * dst = ( char * ) destination;

   for( int i=0; i<size; i++ )
      dst[i] = 0x00;
}



void Process( char * buffer )
{
   Sleep( 1000 );
   cerr << "Envoye   < " << buffer << endl;
   int    size   = strlen( buffer );
   int    retVal = send( to_server_socket, buffer, size, 0 );

   char buf[ 1024 ];
   buf[0] = 0x00;
   while( !buf[0] )
      int yeah = recv( to_server_socket, buf, 1024, 0 );
   cerr << "Recu     > " << buf << endl << endl;
}



int main( int argc, char *argv[] )
{
   int           not            = 0;
   unsigned long ioctl_blocking = 1;

   WSADATA wsaData;
   if( int err = WSAStartup( 0x0101, &wsaData ) )
   {
      cerr << "WSAStartup failed... Error: " << err << endl;
      exit( -1 );
   }


   struct sockaddr_in   serverSockAddr;    // addresse de la socket
   struct hostent     * serverHostEnt;     // description du host serveur
   long                 hostAddr;          // addr du serveur

   bzero( &serverSockAddr, sizeof( serverSockAddr ) );
   // converti l'adresse ip 9.100.1.1 en entier long
   hostAddr = inet_addr( server_name );

   if( ( long ) hostAddr != ( long ) -1 )
      bcopy( &hostAddr, &serverSockAddr.sin_addr, sizeof( hostAddr ) );
   else               // si on a donne un nom
   {
      serverHostEnt = gethostbyname( server_name );
      if ( serverHostEnt == NULL )
      {
         cerr << "ca chie gethost" << endl;
         exit( 0 );
      }
      bcopy( serverHostEnt->h_addr, &serverSockAddr.sin_addr,
             serverHostEnt->h_length );
   }

   serverSockAddr.sin_port = htons( port );         // host to network port
   serverSockAddr.sin_family = AF_INET;             // AF_*** : INET=internet
   // creation de la socket

   to_server_socket = socket( AF_INET, SOCK_STREAM, 0 );
   if ( to_server_socket < 0)
   {
      cerr << "ca chie creation socket client" << endl;
      exit( 0 );
   }

   setsockopt(to_server_socket, SOL_SOCKET, SO_DONTLINGER, (char *) &not,
              sizeof(not));


   // requete de connexion
   if( connect( to_server_socket, ( struct sockaddr * ) &serverSockAddr,
                                      sizeof( serverSockAddr ) ) < 0 )
   {
      cerr << "ca chie demande de connection" << endl;
      exit( 0 );
   }

   ioctlsocket ( to_server_socket, FIONBIO, &ioctl_blocking );

   char buf[ 1024 ];
   buf[0] = 0x00;
   while( !buf[0] )
      int yeah = recv( to_server_socket, buf, 1024, 0 );
   cerr << "Receive > " << buf << endl << endl;

   Process( "HELO helio_denis\r\n" );
   Process( "MAIL From: <ENVOYEUR>\r\n" );
   Process( "RCPT To: <DESTINATAIRE>\r\n" );
   Process( "DATA\r\n" );
   Process( "Subject: Yeah !!!\r\n\r\nEt voici un petit mail !\r\n.\r\n" );
   Process( "QUIT\r\n" );



   /* fermeture de la connection */
   shutdown( to_server_socket, 2 );

   return( closesocket( to_server_socket ) );
}