[완료]smtp서버와 접속하는 소켓입니다. 그런데 ...

#include < stdio.h >
#include < sys/socket.h >
#include < arpa/inet.h >
#include < stdlib.h >
#include < string.h >
#include < unistd.h >
 
 
int main()
{	
 
	int sock;
	int len = 0;
	char buffer[1000];
	struct sockaddr_in kauServer;
	//char * servIP = "mail.kau.ac.kr";
	char * servIP = "localhost";
	char * hostMsg = "HELO rjaechang";
	char * fromMsg = "MAIL FROM : <a href="mailto:rjaechang@gmail.com" rel="nofollow">rjaechang@gmail.com</a>";
	char * rcptMsg = "RCPT TO <a href="mailto:rjaechang@kau.ac.kr" rel="nofollow">rjaechang@kau.ac.kr</a>";
	char * dataMsg = "fighting";
	char * endMsg = ".";
	char * quitMsg = "QUIT";
 
	sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);	
	if(sock < 0){
		printf("Error");
		exit(1);	
	}
 
	kauServer.sin_family = AF_INET;
	kauServer.sin_addr.s_addr = gethostbyname(servIP);
	kauServer.sin_port = 25;
 
	connect(sock, (struct sockaddr*) &kauServer, sizeof(kauServer));
 
	send (sock, hostMsg, 14, 0);
	len = recv(sock, buffer, sizeof(buffer), 0);
	buffer[len] = 0;
	printf("%s", buffer);
 
	send (sock, fromMsg, 31, 0);
	len = recv(sock, buffer, sizeof(buffer), 0);
        buffer[len] = 0;
        printf("%s", buffer);
 
	send (sock, rcptMsg, 27, 0);
	len = recv(sock, buffer, sizeof(buffer), 0);
        buffer[len] = 0;
        printf("%s", buffer);
 
	send (sock, dataMsg, 8, 0);
	len = recv(sock, buffer, sizeof(buffer), 0);
        buffer[len] = 0;
        printf("%s", buffer);
 
	send (sock, endMsg, 1, 0);
	len = recv(sock, buffer, sizeof(buffer), 0);
        buffer[len] = 0;
        printf("%s", buffer);
 
	send (sock, quitMsg, 4, 0);
	len = recv(sock, buffer, sizeof(buffer), 0);
        buffer[len] = 0;
        printf("%s", buffer);
 
	close(sock);
	return 0;
}