I ran across this question recently and thought it to be a good blog post. Basically everyone probably knows what spam is, you probably even check your spam folder when using your email to search for emails that should be in your inbox.
Well in case you didn’t know, spam is unsolicited comments, posts or mail usually robot generated and most of the time unbelievable.
They usually put a link back to some bogus site and make no sense.
Ham on the other hand is user generated and more believable.
If you read the blog, you will see I posted a free plugin to fight both ham and spam.
Also if you have small traffic and don’t mind blocking them IP address at a time, you can open your .htaccess file and add this code:
<IfModule mod_authz_host.c> order allow,deny
(add IP addresses)
Also report them and help yourself at: