Invites and .ics files auto-populate in calendar

[nsmarler]

Is there any way to suppress the behavior of Zimbra to automatically place events from incoming e-mail that has .ics attachments in the user's calendar?

Also, is there a way to toggle invitations as public or private?

Presently, we're trying to share our calendars with a few calendar managers, but the pepperings of unsolicited invites that show in the calendar drives the managers crazy. Short of creating a secondary calendar and sharing it with the managers (thus allowing the default Zimbra calendar instance to receive and display all the invites), is there a way to deal with these? Maybe a way to turn off this auto-populate behavior?