…html- és url-encoding segítségével.
Forrás (JS-verzió): http://www.metaprog.com/samples/encoder.htm (2003)

PHP-funkció (futtatható): http://ideone.com/AUfv3o

// SPAM-PROTECTED MAILTO LINKS WITH HTMLENTITIES & URL-ENCODED CHARACTERS v2.0 - To, CC, BCC, Subject 
// HTML-EXAMPLE:	http://jsfiddle.net/krabat1/2v8ef5jc/
//					http://codepen.io/krabat1/pen/zgswr
 
function spamsafe($email,$text = NULL,$cc = NULL,$bcc = NULL,$subj = NULL,$body = NULL){
	if( isset( $email ) ){
		if(!filter_var($email, FILTER_VALIDATE_EMAIL)){
			echo('not valid');
			return false;
		}else{
			$pattern="/([!#$%&'*+\/=?^_`{|}~\-@\.])/";
		// email
			if( $matches = preg_split($pattern, $email,NULL,PREG_SPLIT_DELIM_CAPTURE) ){
				$str1='';
				$str2='';
				foreach($matches as $element){
					if( strlen($element)>1 || preg_match("/([a-z0-9])/",$element) ){
						$m2 = preg_split("//", $element, -1, PREG_SPLIT_NO_EMPTY);
						foreach($m2 as $m3){
							$str1.='%'.strtoupper(dechex(ord($m3)));
							$str2.='&#'.ord($m3).';';
						}
					}else if( preg_match($pattern,$element) ){
						$str1.='&#'.ord($element).';';
						$str2.='&#'.ord($element).';';
					}
				}
		// elements
				$elements = array('mailto',':','?','&','=','cc','bcc','subject','body');
				$elements_r = array();
				foreach($elements as $e){
					$e = preg_split("//", $e, -1, PREG_SPLIT_NO_EMPTY);
					$e_r='';
					foreach($e as $e2){
						//if( preg_match("/([a-z0-9])/",$e2) ){
						//	$e_r.='%'.strtoupper(dechex(ord($e2)));
						//}else{
							$e_r.='&#'.ord($e2).';';
						//}
 
					}
					array_push($elements_r,$e_r);
				}
				$mailto_str = $elements_r[0];
				$colon_str = $elements_r[1];
				$question_str = $elements_r[2];
				$amper_str = $elements_r[3];
				$equals_str = $elements_r[4];
				$cc_str = $elements_r[5];
				$bcc_str = $elements_r[6];
				$subject_str = $elements_r[7];
				$body_str = $elements_r[8];
 
		//texts
			$texts=array('text' => $text,'cc' => $cc,'bcc' => $bcc,'subj' => $subj,'body' => $body);
			$texts_r=array();
				foreach($texts as $tk => $tv){
					if( !is_null($tv) ){
						$tv2 = preg_split("//", $tv, -1, PREG_SPLIT_NO_EMPTY);
						$str='';
						if($tk=='cc'){
							$str.=$cc_str.$equals_str;
						}else if($tk=='bcc'){
							$str.=$bcc_str.$equals_str;
						}else if($tk=='subj'){
							$str.=$subject_str.$equals_str;
						}else if($tk=='body'){
							$str.=$body_str.$equals_str;
						}
						foreach($tv2 as $tv3){
							//$str.='%'.strtoupper(dechex(ord($tv3)));
							$str.='&#'.ord($tv3).';';
						}
						$texts_r[$tk]=$str;
					}
				}
				//$texts_rk=array_keys($texts_r);
				if( isset($texts_r['text']) ){
					$text0=$texts_r['text'];
					unset($texts_r['text']);
				}
				$texts_rv=array_values($texts_r);
		//start final string
				$final='<a href="'.$mailto_str.$colon_str.$str1;
 
				if( count($texts_rv) > 0 ){
						$final.=$question_str.implode($amper_str,$texts_rv);
				}
				if( isset($text0) ){
					$texts_r=array('text' => $text0);
				}
				$final.='">';
				if( is_null($text) ){
					$final.=$str2;
				}else{
					$final.=$texts_r['text'];
				}
				$final.='</a>';
				return $final;
			}
		}
	}
}
 
echo( spamsafe('recipient@domain.com') . '
<br/>');
echo( spamsafe('recipient@domain.com','Email Us!') . '
<br/>');
echo( spamsafe('recipient@domain.com','Email Us!','other@domain.com') . '
<br/>');
echo( spamsafe('recipient@domain.com','Email Us!','other@domain.com',NULL,'Enquiry regarding product #0022') . '
<br/>');
echo( spamsafe('recipient@domain.com','Email Us!','other@domain.com','hidden@domain.com','Enquiry regarding product #0022','I would like more information on product #0022') . '
<br/>');

Simple
recipient@domain.com
Link text
Email Us!
Link text, cc
Email Us!
Link text, cc, subject
Email Us!
Link text, cc, bcc, subject, body
Email Us!