Blog spam
Pheeewww… I finally installed Akismet to catch all the annoying blog spam. It works surprisingly well. 
I get a couple of blog spams per week instead of the hundreds per week that went to my mailbox before.
I used to run just the Math Comment Spam Protection Plugin, but the spammers easily went through it.
I will go through the Wordpress site and play around with some of the plugins. Hopefully, there will something that I can use.