gistfile1.txt

<?php

function edd_gf_add_priority_to_tags( $tags, $feed, $entry, $form ) {
	$email_id = $feed['meta']['customer_email'];
	$email    = $entry[ $email_id ];
	$user  = get_user_by( 'email', $email );
	if( $user && rcp_is_active( $user->ID ) ) {
		$tags[] = 'priority';
	}
	return $tags;
}
add_filter( 'gform_helpscout_tags', 'edd_gf_add_priority_to_tags', 10, 4 );