Note that this is a basic addon, for a more complete and full featured addon check out shotsters block.
What it is
Whenever you post your email address to a web page, it is readable by search bots. This also means that spam bots can read it, and your inbox piles up with spam. This block will allow you to post your email on a website without fear (see http://techblog.tilllate.com/2008/07/20/ten-methods-to-obfuscate-e-mail-addresses-compared/ for results), keeping your inbox clean!
NEW IN 2.0!
Developer helper for encrypting email. See documentation page.
How it works
what it does is it takes your inputed email address and replaces the @ character with a random 7-digit number, and then the @ character, so for firstname.lastname@example.org it would output for email@example.com. The 7-digit number is wrapped in a span with the style of display: none; so you visitors will see firstname.lastname@example.org, which they can copy and paste into their email client.
In edit mode the link appears as plain text, don't be worried by this