Add option to temporarily pause/disable domain, so it can be reactivated later
Along with delete domain at bottom of domain page, add a pause/disable domain, so all mail for all credentials can be paused if problem occurs + resumed when problem is cleared.
Simon Herbst commented
I have the same issue, the workaround i did was to edit the DNS records to forcibly invalidate the domain.
It works for now but having the option to toggle a domain would be a lot better