You can easily encode mailto and plain email address links on your WordPress site and hide them from spambots. Email Encoder Bundle is a free WordPress plugin that plugin works directly when activated. Simply install and activate it, after activation visit your admin area Dashboard -> Settings -> Email Encoder Bundle plugin option page and check where you want options to take effect like you can enable it on all posts, comments and text widgets. You can set it to automatically encode both mailto and plain email addresses links, you can set class for mailto links and there are few more useful options.
Here is an easy way for protecting your WordPress site’s email addresses from email-harvesting robots by encoding them into decimal and hexadecimal entities.