Zimbra Collaboration Suite 7.0
Zimbra Collaboration Suite 7.0
Multi-Server Installation Guide
Open Source Edition

Multiple-Server Installation > Note about MTA servers

Note about MTA servers
New installs of ZCS limit spam/ham training to the first MTA installed. If you uninstall or move this MTA, you will need to enable spam/ham training on another MTA, as one host should have this enabled to run zmtrainsa --cleanup. To do this, set zmlocalconfig -e zmtrainsa_cleanup_host=TRUE.