When using the Email Copy and Deliver a Secure Link options (without the Desktop Email Integration enabled) you will have an "address book" available to you.
When entering an email address, that email address is added to your address book after the email message is sent. The next time you want to enter that email address, it will be available to you in a type-ahead drop-down.
To remove an email address from the address book, search for the address, hover over it, then click the X icon next to the address to remove it.
The Email Link option does not have this address book available, because you will either be able to locate a recipient in your Outlook address book, or select from the list of other users who have access to the document (the document link will only be useful for those who have access to the document.)