[exim] No keep and sieve

Hello!

Although it seems good documented i don't understand my behaviour of
sieve scripts under exim. I have a very simple sieve script like that:

# Sieve filter
keep;

The message i get for "exim -bf filterfile < mail" is always "No keep".
That also happens if i use bigger filterfiles, even copy and pasted ones
seems to fail. Exim filtering and .forward just work just normal.
What would that "No keep" mean except that exim does not want to keep my
mail?

Mario

--
Chaos reigns within.
Reflect, repent, and reboot.
Order shall return.