note 118591 added to filter.filters.validate

FILTER_VALIDATE_EMAIL not only doesn't support whitespace folding and comments. It only checks Addr-spec part of email address. Otherwise it should mark such address as valid: 'Test Example <test@example.com>' because it is valid according to RFC 822. Also address "test@localhost" should be valid. Which is mentioned in another note. You can test it with this code: <?php $emails = array( 'Test Example <test@example.com>', 'test@localhost', 'test@localhost.com' ); foreach ($emails as $email) { echo (filter_var($email, FILTER_VALIDATE_EMAIL)) ? "[+] Email '$email' is valid\n" : "[-] Email '$email' is NOT valid\n"; } ?> Output for PHP 5.3.21 - 7.0.1 : [-] Email 'Test Example <test@example.com>' is NOT valid [-] Email 'test@localhost' is NOT valid [+] Email 'test@localhost.com' is valid ---- Server IP: 72.52.91.14 Probable Submitter: 188.33.214.243 ---- Manual Page -- http://php.net/manual/en/filter.filters.validate.php Edit -- https://master.php.net/note/edit/118591 Del: integrated -- https://master.php.net/note/delete/118591/integrated Del: useless -- https://master.php.net/note/delete/118591/useless Del: bad code -- https://master.php.net/note/delete/118591/bad+code Del: spam -- https://master.php.net/note/delete/118591/spam Del: non-english -- https://master.php.net/note/delete/118591/non-english Del: in docs -- https://master.php.net/note/delete/118591/in+docs Del: other reasons-- https://master.php.net/note/delete/118591 Reject -- https://master.php.net/note/reject/118591 Search -- https://master.php.net/manage/user-notes.php