You can view your email history to see what emails you have received and where they were moved to.

To view the email history, open the left side panel, tap on "History". There you will see the list of all processed emails and their actions. Tap on an email subject to view the email if it is still available.
You can undo an action (such as a move) by tapping on the checkbox beside an action to select it and then select "Undo" in the action menu in the top right.
Use the search button in the top to search for an email subject other value.

Emails processed by email rules will show in the history as well as which rule attribute the email matched and what happened.

You can view previous days using the book button in the top of the screen.

You can change the number of days of history that are kept using the app settings (View) - Email Management section. You can also disable the email history by setting the history days value to zero. This will improve the speed of processing emails.
You can turn off the history for bulk actions such as delete and move. This is below the history days setting and will also improve performance.