I doubt a court would make a distinction. The claimant (plaintiff) would have to prove the defendant knew about the emails being sent to the public blockchain a

I doubt a court would make a distinction. The claimant (plaintiff) would have to prove the defendant knew about the emails being sent to the public blockchain and decided not to do anything about it. That's not necessarily easy to prove, in the same way the defendant could claim emails were trapped in spam filters, etc. or more realistically, the burden of proof is on the claimant so the defendant wouldn't say anything if they're smart.