Using Classic Outlook on Windows for personal email, calendar, and contact management
Hello
Many users seem to have this issue recently. Microsoft is still investigating this issue. The current workaround is published here: https://support.microsoft.com/office/users-get-errors-0x800ccc0e-0x800ccc0f-synchronizing-gmail-and-yahoo-accounts-in-classic-outlook-e5a7b684-7c5c-4848-ab2d-d48291451f67