Mailshell is usually bundled with Mailspect MPP packages. "mailshell" should be listed in "scan_engines" line of /usr/local/MPP/mppd.conf.xml in order to integrate Mailshell.

An hourly cron job for /usr/local/MPP/mailshellupdate should be setup to keep Mailshell engine updated.

For Mailspect Standard please check Install/Update Mailshell SDKon how to install Mailshell.