Ian, I'm interested to know why you think that the offence being committed by sending the message without any person seeing the message or being offended by is a 'chilling Kafka-esque' twist. It simply means that, for example, if the message is intercepted before being recieved, or sent to someone who isn't offended, but the message is still offensive, the sender can till be prosecuted....
It's simply to stop some smart-arsed social parasite of a solicitor getting someone off an offence of sending a grossly offensive message by saying 'Ah, but the person it was sent to didn't receive it' or 'They weren't offended by it' when the message was still offensive. It makes sense to me....