You can delete the personal message folders you have created on your device. You cannot delete the default folders: Inbox, Outbox, Drafts, and Sent.
To be able to delete a folder, your device must be connected to the PC.
To delete a folder, do the following:
Under My folders, right-click the folder of your choice.
From the pop-up menu, select Delete.
Click Yes to confirm deletion.
The folder is deleted.