Yes you can block them but how can you stop tickmaster.com / ticketmaster.co.uk et al from spamming you anything even though your profiles says “I DON’T WANT YOUR EMAIL CRAP”
After one too many ticketmaster spam here is what you do:
Cancel your account
You have to ask them to do it, as you cannot delete your account like you might from many proper websites but some retard at ticketmaster has to do it and will delete it.
So that fixes ticketmaster spam issues, so remember cancel your account to stop the spam.