5.5->2003. Communication problem after adding 2k3 server

[NipsMG]

I have the MS Document on "Migrating from Exchange server 5.5".

Here's what I did, in order.
Logged onto Exch 5.5 Server.
Ran ForestPrep
Ran DomainPrep
Installed AD Connector
Ran ADC Tools

Logged onto new server.
Installed exchange 2003 on new server, joining the organization.
Copied one mailbox to new server (John Smith) using wizard.

Logged onto a client PC w/ user John Smith.
Successfully configured and launched outlook, pointing at the new exchange server.
Created New E-Mail
Clicked "To"
Selected normal exchange user from list.
Sent e-mail to exchange user.
Got undeliverable:
The e-mail address could not be found. Perhaps the recipient moved to a different e-mail organization, or there was a mistake in the address. Check the address and try again.The MTS-ID of the original message is:c=US;a= ;p=MPI;l=EXCHANGE-041222164940Z-4
MSEXCH:MSExchangeMTA:MPISEY:EXCHANGE


Open outlook using a normal exchange user on old 5.5 server.
Try to send e-mail to John Smith (Name is in directory, selected it by clicking "To", browsing.
Get Underliverable Message:
he following recipient(s) could not be reached:

John Smith on 12/22/2004 12:26 PM
A required directory operation was unsuccessful
The MTS-ID of the original message is: c=US;a= ;p=MPI;l=MPI_MS-041222172552Z-771
MSEXCH:MSExchangeMTA:MPISEY:MPI_MS


Any ideas where I went wrong on this?

--Michael Gerety