That $0.19's not pure profit. There are fixed costs to providing service to all these addresses, sure, but even so, bulk mail has to add expenses on top of that

That $0.19's not pure profit. There are fixed costs to providing service to all these addresses, sure, but even so, bulk mail has to add expenses on top of that, for transportation, storage, and delivery. The fee to end junk mail would only need to cover the net income from that, not the gross.