Using Classic Outlook on Windows for personal email, calendar, and contact management
Hi Donna Jackson4,
Welcome to post your concern in community.
Yes, you're right. The truth is that IMAP protocol doesn't support sync calendars, that's the limitation of this protocol.
If you add an IMAP account as your first account then a default Calendar folder is created in the IMAP store which of course is only a local copy. And you will notice "This computer only" when you check this calendar in Outlook Calendar view. For full Calendar synching and related features, you'll need an Exchange account such as Outlook.com (free) or Office 365. The Exchange accounts support sync all data automatically, your information is always up to date in Outlook and on the server that is running Microsoft Exchange Server. You can refer to this KB to know the limitations of different type of accounts on Outlook: Sync basics - what you can and cannot sync
If you're using Gmail accounts, to keep imported calendar up-to-date, you can subscribe Google Calendar in Outlook. Please check this KB: See your Google Calendar in Outlook
Feel free to contact if you have any further concerns or need more help, we're always glad to share our experience with you :)
Best Regards,
Shawn