PHP Email Validation

<?php
$email_a = 'joe@example.coddddm';
$email_b = 'bogus';

if (filter_var($email_a, FILTER_VALIDATE_EMAIL)) {
    echo "This (email_a) email address is considered valid.";
}
if (filter_var($email_b, FILTER_VALIDATE_EMAIL)) {
    echo "This (email_b) email address is considered valid.";
}
?>