Hi Mugsman3,
I did some further tests on my side.
1. I make serviceadmin’s main calendar not shared (Other users have no permission to the main calendar).
2. And then “serviceadmin” shares the secondary calendar with user2.
3. User2 tries to open this shared calendar using the steps above.
4. Now, on step 4, click OK. I get the following message:
5. Click Allow.
6. Now, both the main calendar and the secondary calendar are displayed under Shared Calendars.
The difference is that: as the main calendar is not shared, when I locate the main calendar (“Calendar”), I cannot see any events in this calendar. And I can see the events in the secondary calendar.
You said “the user opening the shared secondary calendar (in screen shot #4) gets an error as you would expect”, what is the detailed error message?
Moreover, you also mentioned shared mailbox. You’re right, shared mailbox is also a very good choice.
If any step is not clear, please do not hesitate to post back. We are very glad to provide further assistance.
Thanks,
Young Yang