dovecot - Sep 2010 - Question about LDA+spamassassin

Hello

     I am using dovecot 1.2.11 (openexchange not still fully supported 
with dovecot 2.0). In my setup I use ldap to store quota information, 
and I want to accomplish the following: per-user spamassassin rules (MDA 
style), but my setup has the following requeriments:

mail_uid= entrega
mail_gid= entrega

LDA & SIEVE:

sieve_dir=/buzones/my_domain/%2.26Hn/%2.200Hn/%n/sieve/
mail_location=maildir:/buzones/my_domain/%2.26Hn/%2.200Hn/%n


     I have been reading in the wiki, but I am not sure how I can have 
in $mail_location/user1 a .spamassassin directory per-user and lda+sieve 
work together to make spam rules by user

     Regards

     Javier