Neither do I, which is why I posted this as a feature request.
Yes, understood. But going to that page and pressing refresh every few minutes seems rather inefficient.
A plugin would be fine, but I’m not sure why this feature coudn’t just be added to Discourse. To me, it seems like a no-brainer. Discourse already sends various alerts to site admins and staff. Make the setting (alert on email rejection) default to disabled, which I guess would work for many sites.