It's the fucking spit of rudeness to message someone and then give them no way to reply.
It's rude, it's a 'fuck you' move, and if you went to school in the 80's (or even 90's) then you're old enough to know better.
So fuck me? No -fuck YOU.
That's a block.
(yes, I know the irony of posting a 'fuck you too' response they'll never read. Cest le' Guerre tho)