I just got a really vulgar comment, which turned out to be spam. I saw it when I checked my email. It was embarrassing so I rushed to that posting to delete it before anyone else saw it. But, the comment wasn't there. So I fiddled around with my email, but couldn't figure out why it didn't post. Then I went to the blog template and saw the "spam" box that I didn't realize was incorporated into blogger. When I went there, not only were there about 15 really nasty spam messages, but there were some perfectly legitimate comments. So if someone wrote a comment and thought I deleted it or something, not so. It got stuck in the blogger spam box and I never knew it was written. What I can't understand is that many of these never turned up in my gmail at all, unlike the one that prompted me to look for it on the posting. Most of the comments that got caught in the blogger spam filter were anonymous comments, for what it's worth.
I know you can use comment moderation, too. But that's time consuming and slows down the give and take on the blog. So I suppose for the time being I'll just have to start checking the blogger spam filter and releasing the legitimate comments.