Sorry to hear about the comment spam that you're seeing. Basically, this is a common problem with many blogs. Basically, some unscrupulous people just bomb websites (especially WordPress websites) and email with spam. There are methods in preventing spam. You can use a plugin called WordPress re-Captcha. This is one of many methods you can use to help prevent comment spam. You can also go to the Wordpress.org site, and search for the other Wordpress plugins that help with spam. Also, if you have not updated Wordpress, it's highly recommended. They patch security holes and if you're using an older version it's possible to get hit with possible hacks that can lead to issues like comment spam.
Sorry for the headache! Hopefully, this suggestion and your option to delete the comments as per your previous question will help you get rid of the comments quickly.