Email to ascii uses the ‘the_content’ filter to automatically encode any string looking like an email address to ascii characters.

Bots crawl the web in search for email addresses all day long and writing it in plain character is just suicide for your mail box.

By turning the characters into ascii entities I assume that bots will not see the email address as what it is but just as a very long string of weird stuff.

There is no backend to this plugin because of its simplicity, you just enable it and off you go.

Download it from the WordPress repository here