simplesmtp.php

<?php
function smtpSend($to, $from, $message, $host, $port, &$error){
  $recipientString="";
  if ($h = fsockopen($host, $port, $errno, $errstr, 5)){
    $data = array();
    array_push($data, 0);
    array_push($data, "EHLO $host");
    array_push($data, "MAIL FROM: <$from>");
    if(is_array($to)){
      foreach ($to as $toRcpt) {
        array_push($data, "RCPT TO: <$toRcpt>");
        $recipientString = $recipientString.$toRcpt.",";
      }
    }else{
      array_push($data, "RCPT TO: <$to>");
      $recipientString = $to;
    }

    array_push($data, "DATA");
    array_push($data, $message."\r\n.");
    foreach($data as $c){
      $c && fwrite($h, "$c\r\n");
      do{
        $r = fgets($h, 256);
        if(substr($r,0,1)==="5"){
          $error = "SMTP ERROR: ".$r;
          return false;
        }
      }while(substr($r,3,1)==="-");
    }
    fwrite($h, "QUIT\r\n");
    $r = strtolower($r);
    if(substr($r,0,6)!=="250 ok"){
      $error = "SMTP ERROR: Last response was not 250 OK but: ".$r;
      return false;
    }else{
      return true;
    }
    return fclose($h);
  }
  $error = "Could not send mail, fsockopen failed";
  return false;
}
?>