メーラー　１１行。

#include <stdio.h>
#include <winsock.h>
#define k send(s,t,l,0);Sleep(999);while(z=recv(s,t,99,0)){t[z]=0;printf("%s",t);}
#define sp sprintf
main(int c,char **a){SOCKADDR_IN d;WSADATA w;char t[99],z,l;SOCKET s;
WSAStartup(MAKEWORD(2,2),&w);s=socket(AF_INET,SOCK_STREAM,0);if(c!=2)return;
d.sin_family=AF_INET;d.sin_port=htons(25);d.sin_addr.s_addr=inet_addr(a[1]);
if(!connect(s,(PSOCKADDR)&d,sizeof(d)))
{l=sp(t,"HELO %s\r\n",a[2]);k;l=sp(t,"MAIL FROM:%s\r\n",a[3]);k;
l=sp(t,"RCPT TO:%s\r\n",a[4]);k;l=sp(t,"DATA\r\n",a[4]);k;
l=sp(t,"Subject: %s\r\n",a[5]);k;l=sp(t,"%s\r\n",a[6]);k;
l=sp(t,"\r\n.\r\n");k;l=sp(t,"QUIT");k;}closesocket(s);}