$re = '/OLSHANPROPTY_D0C|has\ been\ limited|We\ have\ locked|has\ been\ suspended|unusual\ activity|your\ (customer\ )?account\ has|your\ (customer\ )?account\ was|new voice(\ )?mail|Periodic\ Maintenance|refund\ not\ approved|account\ (is\ )?on\ hold|secure\ update|temporar(il)?y\ deactivated|verification\ required|shared an important document|shared with you|gorgeous women|email quota|someone attempted to login|sign-in attempt|email verifications needed|undelivered mails|your mailbox|outlook corporation|mailbox administrator|email administrator|someone attempted to access|office365 user|deactivate 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