Unblocking a site I accidentally blocked

Question

I accidentally blocked a site that I really still want to receive. I thought there should just be an "unblock" option, too, but I'm realizing it's not that easy. I wish they'd at least asked, "Are you sure?" (If I still had kids at home, I'd probably know more about that!) Is there an EASY way to do this for a 61-year-old grandma? The site is [e-mail].