Alright, we have an Active Directory user, Chuck Cable, and he is using MS Outlook 2002 on an Exchange server. When Chuck sends an email to a specific email address outside of our organization, the email shows "From: Stanton, Tommy" on the email at the recipient's end. Tommy Stanton used to work for our company several years ago, but his account is not even in our AD any more. The account isn't just disabled, but it has been removed altogether a long time ago.
When the recipient replies to this email, it goes back to Chuck's inbox, but the person addresses him as Tommy Stanton because that's how it appeared on the recipient's end. The attached text file is a set of exchanged emails between Chuck and the recipient, Pam, who eventually refers to Chuck as Tommy. I hope that makes sense.
I have checked his AD account's properties and didn't notice anything strange. His Outlook settings all look right, there are no delegates set. Is this possibly just a caching issue on the other organization's end? As far as I know, Chuck tells me this is the only person who replies and addresses him as Tommy.