> Well either there's a bounce, or some other indicator in the postfix logs (collected by filebeat, with alertings in kibana).
The most common type of problem is that mail is delivered but placed into the spam folder. You will not be notified of this with a bounce or anything in your postfix logs.
> If I'd still be getting blackholed with a "250 delivered" in my logs, then screw it.
This is another type of problem I've encountered. It's rarer than the spam folder, but it happens.
