If you are receiving spam emails relating to comments on your blog you can choose to disable comments on your blog or to enable and configure third party spam prevention services, such as Akismet:
How to manage comments
Combating Comment Spam:
If you decide to continue to use comments functionality the Akismet Anti-Spam plugin is already activated and installed on your site. You can further configure this plugin from here: Dashboard > Settings > Akismet.