Windows XP Send To command not working

Whenever I try to use the “send to” command from a windows program such as word, excel or another application, I get the following message back in my inbox:

Your message did not reach some or all of the intended recipients.

Subject: PayrollInstrupr.doc
Sent: 1/23/2003 9:26 AM

The following recipient(s) could not be reached:

‘Joe@XXX.NET’ on 1/23/2003 9:26 AM
The recipient name is not recognized
The MTS-ID of the original message is: c=US;a= ;p=server1;l=PDCSERVER1-030123142559Z-391
MSEXCH:MSExchangeMTA:PDCSERVER1:PDCSERVER1

This started when I purchased a new computer running Windows XP and Office 2002. We use Exchange server 4.5. All other computers on the network are runningWIN98, Office 2000.