$re = '/share(d)?\ an important document|
shared with you|
gorgeous\ women\ | email\ quota\ |
someone attempted to login|
sign-in attempt email verification\'s needed|undelivered mails|your mailbox|outlook corporation| mailbox administrator|email administrator|someone attempted to access|office365 user|activate your mailbox/m';
$str = '';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
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