As Retain gathers mail from users of the targeted message system, it stores the users in the System Address Book, which is cached locally on the Retain server.
As new users have messages archived, they are added to the address book.
The address book contains all users (current and past) who have archived data.
As long as users have archived messages, they cannot be removed from the address book.
Retain distinguishes between multiple users with the same name. For example,
John Smith
added today, is a different user from
John Smith
who began working at the company six months ago, and from
John Smith
who left the company last year.