Question about Bayesian feature

Hi all, I using Fortimail 400E , Firmware version: v5.3,build653,180328 (5.3.12 GA) , Operation mode : Gateway , 3 Exchange 2013 servers behind, I have about 10 email domains , I want to use global bayesian database for all I read about Bayesian training here : https://help.fortinet.com/fmail/archives/3_0/fortimail-admin/wwhelp/wwhimpl/common/html/wwhelp.htm?context=FortiMail_Online_Help&file=FortiMail_Online_Help-12-13.html I don't understand part To perform ongoing training of each per-domain Bayesian database  Should I create mailboxes learn-is-spam@example.com , learn-is-not-spam@example.com ... myself ? How Fortimail bayesian can access to these mailbox and learn ?