The steps to set this up are simple:
To approve the sender's e-mail address:
1. Visit Manage Your Kindle
2. Sign-in to Amazon
3. Go to "Personal Document Settings" under "Your Kindle Account".
4. Under "Approved Personal Document E-mail List" click "Add a new approved e-mail address". 5. Enter the e-mail address to approve and select "Add Address."
If you've only downloaded the add-ons, but not signed up for an account, you can enter your Kindle's email address at http://readability.com/kindle/setup instead.
Once you're set up, Readability will remember your settings.
*Amazon provides incoming email addresses for Kindle devices and the most recent iOS apps. You'll need the latest version of the Kindle app for iOS.