Index: src/include/lib/Garradin/UserTemplate/Modifiers.php
==================================================================
--- src/include/lib/Garradin/UserTemplate/Modifiers.php
+++ src/include/lib/Garradin/UserTemplate/Modifiers.php
@@ -1,10 +1,12 @@
 <?php
 
 namespace Garradin\UserTemplate;
 
 use Garradin\Utils;
+
+use KD2\SMTP;
 
 class Modifiers
 {
 	const PHP_MODIFIERS_LIST = [
 		'strtolower',
@@ -39,10 +41,11 @@
 		'xml_escape',
 		'replace',
 		'regexp_replace',
 		'remove_leading_number',
 		'get_leading_number',
+		'check_email',
 	];
 
 	const LEADING_NUMBER_REGEXP = '/^([\d.]+)\s*[.\)]\s*/';
 
 	static public function replace($str, $find, $replace): string
@@ -52,10 +55,15 @@
 
 	static public function regexp_replace($str, $pattern, $replace)
 	{
 		return preg_replace($pattern, $replace, $str);
 	}
+
+	static public function check_email($str)
+	{
+		return SMTP::checkEmailIsValid($str, true);
+	}
 
 	/**
 	 * UTF-8 aware intelligent substr
 	 * @param  string  $str         UTF-8 string
 	 * @param  integer $length      Maximum string length