WordPress.org

EMAILProtect hides a normal e-mail string (e.g. "info@domain.com") by editing the HTML code. This does not effect the outcome as the normal user sees it, but it make's it impossible for web crawlers to locate the e-mail address.

Most crawlers these days are "non-javascript crawlers" (to speed up the crawling process) which means that almost no crawlers can see the re-written e-mail addresses - even though it looks just the same for the regular user.

If you look in the source code of you WordPress page, with this plugin activated, you will see a JavaScript (e.g. <script type='text/javascript'>plug_emp('3;4;1;6#cominfo1domain');</script>) where it's supposed to be an e-mail address.