Which Outlook folder contains the most mail?
If your mailbox is too full and you would like to know which folder contains the most email you can do this in the following way:
Right-click on the inbox of the account whose size you want to know.
Then click on the "folder size" button.
You can now see which folder has the most emails so you can clean up in a targeted way.
Don't forget to empty the recycle bin after deleting emails !