I have enabled the Exchange POP3 service on our Exch200
server (running on Win2003 server) so our Mac user
can connect using the Entourage v10 client.  They ar
able to receive external and internal email, tasks, calendar
etc. but they cannot send external mail.  They get a message
"....there is an undelivered  message in your outbox, eithe
the receipient is not valid or Exchange does not
recognize the user ID.  Explaination: exchange will not relay
the message to "email@address

Do I have to make special settings to the Exch user accounts o
my mac user logon id's

Thanks in advanc
Patric