are there any other folders inside it?
Gmail has a habit of creating this folder which is dependent on the settings you have in Gmail.
Log on to gmail in your browser.
Go to "settings"
Click on "labels"
Find the "all mail" label and uncheck "show in IMAP"
The label/folder should no longer appear on your Apple Mail folder list the next time you start Mail.
Let us know how you get on
Have over 250,000 messages in my Mail Archive folder. I have tried deleting them, but they just repopulate. Would like to get rid of Archive folder altogether but the delete folder option is not available . What can I do?