Spam email through comments

Not quite sure what you mean by spam email from comments because spam email and spam comments aren’t the same thing. Do you mean you’re getting spam emails through a contact form you have on your WordPress site?

Do you have any comment spam plugins enabled, e.g., Akismet?

(Also, a link to your site might help.)

Activate Akismet and install http://wordpress.org/extend/plugins/cookies-for-comments/