clear_email.php

<?php
function clear_email( array $contact ) {
	$clean = [];

	foreach ( $contact as $contact_key => $contact_value ) {
	    if ( is_array( $contact_value ) ) {
            $clean[ $contact_key ] = clear_email( $contact_value );
        }
	    elseif ( is_email( $contact_value ) ) {
			$email_parts = explode( '@', $contact_value );
			$clean[ $contact_key ] = implode( '@', [ '***', $email_parts[1] ] );
        }
	    else {
	        $clean[ $contact_key ] = $contact_value;
        }
    }

	return $clean;
}