Ghost Users

Hello. I need some help!

4 years ago, my company split from another company. At the time, we were on
Exchange 5.5 and used the Move Server Wizard to take our users from the old
org to our new one. No problem (yeah, right!).

A couple of months ago, we completed an upgrade to Exchange 2003. Much
smoother. But we seem to have a couple of "ghosts" hanging about. I'll
explain:

We have had a couple of occassions recently where users have sent meeting
requests and received NDRs from people who were not on the recipient list.
The NDRs were from people in the original org... before the companies split,
3 iterations of Exchange ago, and all are employees of the company we split
from. That company has since moved to Exchange 2003 as well, but the NDR
comes back in the Exchange 5.5 format (org, site, container, object). I was
thinking that maybe one of the attendees had these "ghosts" as delagates many
moons ago, but there is no evidence of that in their profiles (no "ghost"
users listed as delagates).

Has anyone ever heard of a similar situation, and if so, what's an
administrator to do? I might also mention that our 2003 was an upgrade, not a
migration. I wanted to migrate, to clean up the pollution, but no, management
didn't want the pain. Wimps!
--
Mark T. Haley
Sys Admin (Exchange)
The Relizon Company