Hey, I recently ran into the same issue where my Outlook Calendar was filled with duplicate meetings and appointments after syncing multiple accounts. Removing them manually was taking forever. After trying a few methods, I found that the SysTools Outlook Duplicates Remover made the process much easier. It can automatically detect and remove duplicate calendar entries based on multiple criteria like subject, date, time, location, and organizer while keeping the original appointments safe. It also lets you preview duplicates before deleting them and works with large PST/OST files without affecting other Outlook data. If you're dealing with a lot of duplicate calendar items, it's definitely one of the easiest and most reliable solutions.