I mentioned the emails just to show that there are those who will defend the indefensible regardless.
I'm not taking them seriously. The addresses are now blocked. Proving from where and who they came from and doing anything with that proof is too long and laborious a process. Not worth the effort.
That someone has my email address is of little concern either. I've had that same address since 1999 and it, and my real world self, aren't too hard to find on the internet.
So, talk of harassment, police, ICO etc, is pointless. It's enough effort just concentrating on the matter in hand - being denied travel at a time of my choosing with a valid ticket.
The emails are just an amusing, to me, sideshow.