$blacklist = ['@email.com', 'N/A', 'n.c@email.com', 'n.c@email.com'];
$date = date('Y-m-d');

foreach ($results->data as $row) {
    $emails[] = $row->guestEmail;
    foreach ($blacklist as $b) {
        if (stripos($row->guestEmail, $b) !== false && date('Y-m-d', strtotime($row->endDate)) == $date) {
            $guests[] = array(
                'FirstName' => $row->guestFirstName,
                'LastName' => $row->guestLastName,
                'email' => $row->guestEmail,
                'country' => $row->guestCountry,
                'check-in_date' => $row->startDate,
                'check-out_date' => $row->endDate,
            );
        }
    }
}