I wonder if anyone has a sitewide config for having the bayes files under the spamd users .spamassassin directory and still let users have their own $HOME/.spamassassin/user_prefs
in local.cf set
bayes_path /home/spamd/.spamassassin/bayes bayes_file_mode 777
And make spamd's home world RWX.. In alternative, you can use a bayes path that's elsewhere, but be sure to end with bayes (this last part is actually part of the filename, not a directory)