Do you also know where the emails are saved? I don't see them in Apple Mail's Outbox or Sent Items.
The reason I ask, is that I want to delete a bunch of old stuff from a Calendar, but do not want the invited people to receive an email. So if I cut my internet connection, remove the events (and click OK to sent a notification that the event was canceled), I can remove those emails before I activate my internet connection.
What happens with invites depends on whether the calendar is local or stored on calendar server or not. For local calendars (those under "On My Mac") the sent items will go into the outbox on Mail while the internat connection is broken. For server based calendars (iCloud, Exchange, Google calendar and other CalDAV calendars) the server is sent a signal via your internet connection and the email is made and sent from the server.
You are not going to be able to stop a server based calendar using the method you subscribe.
For local calendars you might want to look at my application iCal Reply Checker. It is shareware, but runs for 10 days before needing to be paid for.
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