Block email address?

I'm really desperate right now!

I know the question is stupid and unfair, but I don't know any other way to defend myself.

Does anyone here in the community know what happens if I write someone a final email and then block them straight away? Will they still receive this final email? I want them to at least understand why I'm doing it, even though I don't have to justify myself to them, how or why I see it as a last resort. I want to be mean once in my life. It was the first and last time I gave my email address to someone from Facebook. I've been on Facebook for many years and have always been careful, but now this bout of stupidity has bitten me too, and I want to get rid of it. Please, please, can I write my opinion for once without being picked on again? Just once, I really mean it, they're just getting on my nerves. And I can't deactivate my own email address at the moment. It's a good thing I didn't give out my real address and phone number. Still, it was stupid enough of me. Can someone answer my question, please??