HIMS Braille Sense U2 User Manual page 233

You can't delete "Inbox", "Sent", "Outbox". But you can delete the added
folders.
In order to delete the folder, follow these steps:
1) Execute "E-mail" program.
2) Press "Space-m (dots 1-3-4) to call up the menu in mail lists of
"Inbox".
3) It shows "File".
4) Press "Space-4", move to "Edit" and Press "Enter". Or Press "e
(dots 1-5).
5) It shows "Select All".
6) Press "Space-1" or "Space-4", move to "Copy to Mailbox" or "Move
To mailbox".
7) Press "Enter". Or press "Backspace-c (dots 1-4)" or "Backspace-x
(dots 1-3-4-6), without calling the menu.
8) It shows "Folder" lists.
9) Press "Space-1" or "Space-4", move to the folder that you want to
delete.
10) Press "Tab (Space-4-5), move to "Delete mailbox".
11) Press "Enter".
12) It shows "Delete (mailbox name) mailbox? Yes".
13) Press "Enter".
By pressing "Space-d (dots 1-4-5)" on the folder that you want to delete,
you can delete the mailbox.
If you want to cancel this function, press "Tab (Space-4-5) on the
"Confirm", move to "Cancel". And press "Enter".
If you attempt to delete the "inbox", "Sent" and "storagebox," you will
hear the warning sound to notify you of the error.
8.4.4.3 Changing Folder Mailbox
You can't change folder mailbox of the "Inbox" and the "Storagebox".