smtp send mail with C in linux

[Amin Aghakhani]

hi
I wanna send an email to another body.but smtp server sends me some errors that i can't understand why it sends these errors!
plaese help me

here is my code:

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <sys/socket.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <sys/time.h>
#include <iostream>
using namespace std;
int main(void)
{

// set family and socket type
struct addrinfo hints, *result;
memset(&hints, 0, sizeof hints);
hints.ai_family = AF_INET;
hints.ai_socktype = SOCK_STREAM;

// resolve hostname to IP address: specify host and port number (in char not int)
if(getaddrinfo("smtp.gmail.com", "25", &hints, &result) != 0)
{
freeaddrinfo(result);
puts("Could not resolve hostname.");
exit(1);
}
// create socket and free addrinfo memory
int newsocket = socket(result->ai_family, result->ai_socktype, 0);
if(newsocket == -1)
{
puts("Could not create socket.");
freeaddrinfo(result); // free addrinfo memory
close(newsocket);
exit(1);
}

// set socket timeouts
struct timeval timeout;
memset(&timeout, 0, sizeof(timeout)); // zero timeout struct before use
timeout.tv_sec = 5;
timeout.tv_usec = 0;
setsockopt(newsocket, SOL_SOCKET, SO_SNDTIMEO, &timeout, sizeof(timeout)); // send timeout
setsockopt(newsocket, SOL_SOCKET, SO_RCVTIMEO, &timeout, sizeof(timeout)); // receive timeout

// connect to website
if(connect(newsocket, result->ai_addr, result->ai_addrlen) == -1)
{
puts("Could not connect.");
freeaddrinfo(result); // free addrinfo memory
close(newsocket);
exit(1);
}

char t[500];
int y=recv(newsocket,t,100,0);
t[y]='\0';
cout<<t<<"\n";

strcpy(t,"HELO gmail.com\r");
send(newsocket,t,sizeof(t),0);
memset(t,'\0',100);
y=recv(newsocket,t,100,0);
t[y]='\0';
cout<<"message\n"<<t;
memset(t,'\0',100);
strcpy(t,"MAIL FROM: [e-mail]\r");
send(newsocket,t,sizeof(t),0);
memset(t,'\0',100);
y=recv(newsocket,t,100,0);
t[y]='\0';
cout<<"message:\n"<<t<<"\n";
strcpy(t,"RCPT TO: [e-mail]>\r");
send(newsocket,t,sizeof(t),0);
memset(t,'\0',100);
y=recv(newsocket,t,100,0);
t[y]='\0';
cout<<t<<"\n ok\n";
return 0;
}


thanks

[Moschops]

What error?

[Amin Aghakhani]

after sendig MAIL FROM to smtp,every command which you try to send will get back error!

smtp sends me 555 error :O
and sometimes 502 error

my problem is after sendig MAIL FROM to stmp.

[modoran]

gmail DOES NOT use port 25 and the connection MUST BE ssl encrypted, Also stmp service must be activated first from gmail account settings.

I suggest you to use libcurl instead of direcrly using sockets.