Meeting requests received in different Pop3 client

[Jeff]

We have an Exchange 2000 server as well as a Unix email server. I have a
couple people using Outlook 2003 to get mail from the pop3 server as well as
Exchange. The default mail account for these users is the pop3 account.
When these users send meeting requests from Outlook to other users, the
other users receive the request in their POP3 client, not outlook. When I
create a meeting request an explicitly tell it to send through the exchange
server, the other users receive the request properly in Outlook. Prior to
using OL2003 we were using OL2002 and did not have this issue.

Any insight is greatly appreciated.

Thanks,

Jeff