<Possible methods to protect e-mail address from spam bots ⁄ >

<?php
/**
 * Class ProtectEmail
 * 
 * This class implements a few possible methods
 * to protect e-mail addresses from spam bots
 *
 * @author pedrocorreia.net
 */
class ProtectEmail{
  private $_email;
 
  /**
   * Constructor
   *
   * @param String E-mail
   */
  public function __construct($email){
    if($this->_IsValid($email)) $this->_email=$email;
    else throw new Exception("EMAIL_IS_NOT_VALID");
  }
 
  /**
   * "Beautify" e-mail by converting symbols to strings
   *
   * @return String
   */
  public function Beautifier(){
    if(!$this->_email) throw new Exception("EMAIL_NOT_SPECIFIED");
    $search_for=array("/\./","/@/","/-/");
    $replace_with=array(" Dot "," At ", " Hyphen ");
 
    return $this->Encoder(preg_replace($search_for,$replace_with,$this->_email));
  }
 
  /**
   * Encode all elements in a String to their ascii codes
   *
   * note: if no argument's specified, the string encoded 
   * will be the attribute defined in the constructor
   * 
   * @param String [Optional]
   * @return String
   */
  public function Encoder($email=""){
    if(!$email) $email=$this->_email;
    if(!$email) throw new Exception("EMAIL_NOT_SPECIFIED");
 
    $count=strlen($email);
    $encoded_str=array();
    for ($i = 0; $i < $count; $i++){
      $char=ord($email{$i});
      $encoded_str[$i] = "&#$char;";
    }
    return implode("",$encoded_str);
  }
 
  /**
   * Check if is a valid e-mail address
   * 
   * note: complete credits to http://www.ilovejackdaniels.com/php/email-address-validation/
   *
   * @param String
   * @return String
   */
  private function _IsValid($email) {
    // First, we check that there's one @ symbol, and that the lengths are right
    if (!ereg("^[^@]{1,64}@[^@]{1,255}$", $email)) {
      // Email invalid because wrong number of characters in one section, or wrong number of @ symbols.
      return false;
    }
    // Split it into sections to make life easier
    $email_array = explode("@", $email);
    $local_array = explode(".", $email_array[0]);
    for ($i = 0; $i < sizeof($local_array); $i++) {
      if (!ereg("^(([A-Za-z0-9!#$%&'*+/=?^_`{|}~-][A-Za-z0-9!#$%&'*+/=?^_`{|}~\.-]{0,63})|(\"[^(\\|\")]{0,62}\"))$", $local_array[$i])) {
        return false;
      }
    }
    if (!ereg("^\[?[0-9\.]+\]?$", $email_array[1])) { // Check if domain is IP. If not, it should be valid domain name
      $domain_array = explode(".", $email_array[1]);
      if (sizeof($domain_array) < 2) {
        return false; // Not enough parts to domain
      }
      for ($i = 0; $i < sizeof($domain_array); $i++) {
        if (!ereg("^(([A-Za-z0-9][A-Za-z0-9-]{0,61}[A-Za-z0-9])|([A-Za-z0-9]+))$", $domain_array[$i])) {
          return false;
        }
      }
    }
    return true;
  }
 
}
 
?>

<?php
include_once("class.ProtectEmail.php");
 
$email="email@my-domain.com.pt";
 
try{
  $protected_email=new ProtectEmail($email);
}
catch (Exception $ex){
  echo $ex->getMessage();
  return ;
}
 
//we have a valid object
if($protected_email){
  try{
    $email_encoded=$protected_email->Encoder();
  }
  catch (Exception $ex){
    echo $ex->getMessage();
  }
 
  try{
    $email_beautified=$protected_email->Beautifier();
  }
  catch (Exception $ex){
    echo $ex->getMessage();
  }
 
  $email_link="<a href='mailto:$email_encoded'>$email_beautified</a>";
 
  echo "$email_encoded<br/><br/>$email_beautified<br/><br/>$email_link";
}
 
?>