$re = '/^([-!#$%&\'*+/=?^_`{}|~0-9a-zA-Z]+(\.[-!#$%&\'*+/=?^_`{}|~0-9a-zA-Z]+)*|^"([\001-\010\013\014\016-\037!#-\[\]-\177]|\\\\[\001-011\013\014\016-\177])*")@(?:[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,6}\.?$/';
$str = 'da.ni.el@l.ev.ire.cc';
$subst = "";
$result = preg_replace($re, $subst, $str, 1);
echo "The result of the substitution is ".$result;
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php