Forced Errors verified
Fails matching mail with a chosen code instead of delivering it — by destination, sending address, pool or tag.
In detail
Where suppression works on the recipient, a forced error works on the route: this domain, from that address, with that tag. The result is a normal failure carrying our code and description, so it is visible in the result stream rather than silently dropped. The counter of occurrences on each row makes it the only interception that reports how much it caught, which is worth surfacing: a forced error nobody removes is a permanently broken route.