New class for filtering deliveries
Moved another method to DeliveryFilter
Inlined methods
Get rid of small optimisation to allow a refactor
Check each delivery individually whether it can be sent
Rename method
Moved calculation of whether to send a particular delivery to the filter
Rename class
Add tests for the other methods in HoldBackHardBounceFilter
Extract base class for filter
Add guard-rspec
Make filter composable
When queue id and address aren't recognised also spit out the full log line