Best preg_match pattern for e-mail validation?

[jox432]

I'm looking to switch eregi to preg_match as it's faster, found these two patterns on the web, not sure now which is better (the first one is from preg_match manual page as a comment, improved it a bit):

$pattern1 = '/^{[a-z0-9!#$%&+-=?_{|}~]+(\.[a-z0-9!#$%&*+-=?^_{|}~]+)@([-a-z0-9]+.)+([a-z]{2,3}|info|arpa|aero|coop|name|mobi|museum)$/ix';}

$pattern2 = '/^{[\x00-\x20()<>@,;:\".[]\x7f-\xff]+(?:.[\x00-\x20()<>@,;:\".[]\x7f-\xff]+)*@[\x00-\x20()<>@,;:\".[]\x7f-\xff]+(?:.[\x00-\x20()<>@,;:\".[]\x7f-\xff]+)+$/i';}

[NogDog]

preg_match('!([^\x00-\x20\x22\x28\x29\x2c\x2e\x3a-\x3c\x3e\x40\x5b-\x5d\xa6-\xff]+|\x22([^\x0d\x22\x5c\xa6-\xff]|\x5c[\x00-\xa5])*\x22)(\x2e([^\x00-\x20\x22\x28\x29\x2c\x2e\x3a-\x3c\x3e\x40\x5b-\x5d\xa6-\xff]+|\x22([^\x0d\x22\x5c\xa6-\xff]|\x5c[\x00-\xa5])*\x22))*\x40([^\x00-\x20\x22\x28\x29\x2c\x2e\x3a-\x3c\x3e\x40\x5b-\x5d\xa6-\xff]+|\x5b([^\x0d\x5b-\x5d\xa6-\xff]|\x5c[\x00-\xa5])*\x5d)(\x2e([^\x00-\x20\x22\x28\x29\x2c\x2e\x3a-\x3c\x3e\x40\x5b-\x5d\xa6-\xff]+|\x5b([^\x0d\x5b-\x5d\xa6-\xff]|\x5c[\x00-\xa5])*\x5d))*!', $email)

Or, if you'd actually like to be able to sort of understand it:

# email address validation function
# kudos to http://iamcal.com/publish/articles/php/parsing_email/
function is_valid_email_address($email) {
  $qtext = '[^\\x0d\\x22\\x5c\\xa6-\\xff]';
  $dtext = '[^\\x0d\\x5b-\\x5d\\xa6-\\xff]';
  $atom = '[^\\x00-\\x20\\x22\\x28\\x29\\x2c\\x2e\\x3a-\\x3c'.
  '\\x3e\\x40\\x5b-\\x5d\\xa6-\\xff]+';
  $quoted_pair = '\\x5c[\\x00-\\xa5]';
  $domain_literal = "\\x5b($dtext|$quoted_pair)*\\x5d";
  $quoted_string = "\\x22($qtext|$quoted_pair)*\\x22";
  $domain_ref = $atom;
  $sub_domain = "($domain_ref|$domain_literal)";
  $word = "($atom|$quoted_string)";
  $domain = "$sub_domain(\\x2e$sub_domain)*";
  $local_part = "$word(\\x2e$word)*";
  $addr_spec = "$local_part\\x40$domain";
  return preg_match("!^$addr_spec$!", $email) ? 1 : 0;
}