[exim] exim and SpamAssassin on Debian Sarge

Hi,

Being new to Debian, I run now Exim i.s.o. sendmail,
previously I used SpamAssassin in conjunction with Sendmail.
So now I would like to get same setup but wit Exim.
I have installed both SpamAssasin and Exim (SARGE). Exim
is working nicely, configured as Smarthost. I have spamd running,
and can run SpamAssassin from the commandline. However when
I look at the Email headers I can see that the Emails received
are NOT passed through SpamAssassin.

Any pointers to a working setup ?

Thx