I would say that, on average, I receive around half a dozen such emails every day. Some days it is far more, others less. Most come not as comments on the site but to my personal email address. I imagine that is quite normal. Since, given the comments they make, it is clear that the senders are morons, I dismiss them - they really are water off a duck's back. Those that contain direct threats are passed on to the police.
My post below on Xmas has, I suspect, been highlighted on an antisemitic site, since it has prompted a deluge of rants which attack me for being Jewish and daring to write that I only celebrate Xmas as a secular festival. I have allowed to be posted those which aren't antisemitic, merely bizarre, since the twisted logic and weird suppositions on which they are based expose the mindset of those who posted them. I have deleted the others.
The best tactic is usually to ignore them when they come, so usually I do. But here's one, just as an example of what we put up with. I apologise if the language is upsetting, but I think I either post it unexpurgated or not at all: Dirty Jew. You people are so fucking arrogant. You're rich and you play like victims. You destroy the spiritual basis of civilization so you can pick up the pieces and resell them to us with interest. Then you act like we don't know what's going on when you stick to yourselves but want our daughters to fuck niggers so we don't have any more racial pride. Don't think we're fooled. Don't think we can't see your hook noses or notice your unathletic schlebby physiques. You disgusting race of parasites; you're going to play your hand too hard as you've done so often and get destroyed again. I can't wait. Belloc was right. We're watching you Jew. - Hillaire Belloc Fan The words are, of course, a caricature of racist idiocy. But then what else would one expect?