How do I make it so that an email group created in Zoho Mail does NOT have a calendar?

I have a couple groups for our phone systems voicemails - one for each department. Voicemail recordings are sent to this groups email address so they have access to it.

When going to the calendar users now see a bunch of calendars for our voicemails.

I know I can hide or unsubscribe from these, but as an administrator I want to do this for all users by just removing the calendar all together. Telling each person to hide a bunch of calendars will just confuse people. People want to login and have there stuff be setup correctly by default and I do not see a clear way of accomplishing this.