spamassassin user_prefs getting ignore

[Steve Dondley]

I'd like to configure postfix so the configuration settings in the 
per-user configuration file at ~/.spamassassin/user_prefs get applied.

This user_prefs config file is used with the spamassassin command as 
evidenced with spamassassin -D < spam.txt. But as far as I can tell, the 
user_prefs file is ignored when used with postfix. I've got these lines 
line in my master.cf file:

spamassassin unix -     n       n       -       -       pipe
     user=debian-spamd argv=/usr/bin/spamc -f -e /usr/sbin/sendmail -oi 
-f ${sender} ${recipient}