Let's say "Sally Sue" is being terminated. Sally's primary SMTP address was firstname.lastname@example.org.
For starters I'd disable Sally's account so that she can no longer log in or receive mail. I'd then create an alternate address such as email@example.com as a secondary SMTP address on Sally's mailbox. After that I would set firstname.lastname@example.org as the primary SMTP address for Sally, and I would delete email@example.com from the list of SMTP addresses associated with that account. Now I'd wait some time for Active Directory and Exchange to synchronize these changes. Once that's done I'd use my "Terminated Users" catch-all mailbox and add the address firstname.lastname@example.org. This then allows me to capture any subsequent mail sent to Sally after her termination, while still preserving the contents of Sally's mailbox for inspection by HR or other interested and authorized parties. After a good amount of time has elapsed, I'd archive Sally's mailbox and shut it down permanently.
This was first published in August 2004