Using Classic Outlook on Windows for personal email, calendar, and contact management
Could you please clarify whether the invitations arrive in your Inbox but do not appear in the calendar, or whether the invitation emails themselves are missing? Also, is the receiving account an Outlook.com/Hotmail account or a Gmail account configured in Classic Outlook? If the invitations arrive in your Inbox, what happens when you open one and select Accept? Finally, do the missing meetings appear when you access the same account's calendar through its web interface (Outlook.com or Google Calendar)?