Setting SpamAssassin's Bayes_path per user and dovecot

I have dovecot, Spamassassin and postfix running. I started to use sa-learn to get better and more precise spam identification and filtering.

I have not set the Bayes_path preference on my local.cf file, thus when I call sa-learn -u [email protected] --spam, the Bayes DB gets updated at /root/.spamassassin.

I decided then to create a sieve filter on dovecot, as described on Dovecot's wiki page. Basically, Dovecot's sieve plugin execute sa-learn with a -u argument, apparently the same way I do when I use it manually.

BUT, the thing is that when Dovecot executes sa-learn, the bayes database is created on the virtual user's folder, ie., /var/mail/vmail/mydomain.org/user/.spamassassin. When I call it manually, the db used is /root/.spamassassin`

I am now confused as I don't know if, when evaluating spam, spamd will use the Bayes DB on the user's Maildir, or if it will use the one under /root/.spamassassin.

I would really like to have my spam evaluation done per user, not site wide, so I wonder:

• How can I configure bayes_path for each user, individually, on a virtual users setup?
• Does calling spamd with --virtual-config-dir have anything to do with this? I tried it, setting it up with my virtual users path, but it didn't seem to make any difference when it comes to what I describe in this post. With or without it set up, the results above are the same.