I do apologize, Rupert, you are of course absolutely correct.
The same kind of mechanisms that exist in WooCommerce Tickets and EDD Tickets aren’t actually present in the case of Shopp Tickets – but we can probably do something to help even so. Can you try adding this snippet (for instance, to your theme’s functions.php file)?
add_filter( 'wp_mail', 'stop_shopptickets_emails' );
function stop_shopptickets_emails( $atts ) {
// Safety check
if ( ! function_exists( 'shopp_setting' ) ) return $atts;
// This is the email we're looking for
$expected_subject = apply_filters( 'shopptickets_ticket_email_subject',
sprintf( __( 'Your tickets from %s', 'tribe-shopptickets' ), shopp_setting( 'business_name' ) ) );
// If it's not the one, let it go out
if ( $expected_subject !== $atts['subject'] ) return $atts;
// Cludge to stop the email from sending
$atts['to'] = '';
return $atts;
}
Does that help?