#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
 
#define USER "ud12_38"
 
int main()
{
  char *user = getenv("SMTPAUTHUSER");
 
  if (user != NULL && strncmp(user, USER, strlen(USER)) == 0)
  {
    puts("E550 YOU HAVE BEEN BANNED - PLEASE CONTACT UD MEDIA");
    fprintf(stderr, "block: smtp user %s has been blocked\n", user);
  }
  return 0;
}