Hi Lmmd1, It sounds like you opted for the inclusion of Inbox Categories (similar to Gmail) when running the v10 upgrade wizard, in which case, your emails have not disappeared, but have been categorised into different Inboxes based on subject matter. There are some instructions in this post on how to select which categories you would like or none at all - if you prefer the single Inbox approach as per v9. If you still wish to downgrade to v9, there are plenty of posts on this forum on how to go about doing this, so long as you have backed up your v9 database.