1. First set up all your appointments - the only addressee should be yourself. Send the appointment to yourself (this is the secret ingredient) - set up a really good name for the subject like - Dec 8th MTG - 1-2 PM - your invitation may go straight to the deleted folder as unread - if you open it, it says you can't accept because you're the organizer.
2. Find the appointment in the Calendar - select it with one-click, then choose File > Save As and save it as an ICS file - it should save as Dec 8th MTG - 1-2-PM.ics.
Save all the other appointments in the same way - they should be in your documents folder.
3. Write your email to all your recipients - attach all the .ics files you created above
Recipients should then be able to see Accept or Decline or Tentative.
I found that once a meeting was accepted, the recipient wasn't able to decline it anymore.
Test this FIRST with ONE close person who doesn't mind you sending them test emails, because it works for me, but as these things go, it may not work for everyone.