How to Add Another User to Your Kindle
The Amazon.com Kindle allows you to send documents to your device by attaching the document to an email and sending it to your Kindle's unique email address. To stop unknown persons from sending unwanted documents to your Kindle, Amazon.com will only deliver emails from addresses that you have preapproved. If you share a Kindle with a family member, you should add her email to the approved list so that she can send documents to the Kindle.
Go to Amazon.com's Manage Your Kindle Web page. If prompted, sign in to your account.
Scroll down to the "Your Kindle Approved E-mail List" field.
Enter an email address in the "E-mail Address" field. You can also enter just a domain name to allow all email from that domain, such as "@mybusiness.com."
Click "Add Address."