fetchmail multidrop problem

["Marco Scholten" <mmlist@xs4all.nl>]

hello,

I am trying to fetch mail from out ISP and divide it on our lan to the 
correct users.
We have only 1 mailbox with several aliases.

mail to e.fox@ourdomain.nl should go to els
mail to j.jansen@ourdomain.nl should go to jan
mail to th.jansen@ourdomain.nl should go to theo
mail to info@domain.nl should go to els and jan

After several days of reading man pages and googling i still haven't been 
succesfull.

what i have done so far
-installed fetchmail
-installed exim4 and configured it to send using smarthost and receive using 
fetchmail
-configured outlook express on client machines.

.fetchmailrc:

set postmaster "jan"
set no bouncemail
set no spambounce
set properties ""
poll smtp.ourisp.nl with proto POP3 interval 300
   aka ourisp.nl localdomains ourdomain.nl
      user 'jan' there with password 'secret' to j.jansen=jan e.fox=els 
th.jansen=theo here options keep

All messages now go to the postmaster, when i send a mail to 
th.jansen@ourdomain.nl then fetchmail gives an error 'unknown user'.
When i send a mail to theo using 'echo "test" | mail -s "testmsg" theo' then 
it is received ok on the client machine.

i have tried running fetchmail as root and as user, results are the same.

I do not understand the relation between the various programs involved in 
this very well.
Can anyone please point me in the right direction?

thanks,
 Marco.