Deletes either the message you are currently reading or the
    message you just read. Deleted messages are usually moved
    to a folder called WASTEBASKET; however, you can rename your
    WASTEBASKET folder by entering the SET WASTEBASKET_NAME command.

    If you enter the SET AUTO_PURGE command, your WASTEBASKET folder
    is emptied automatically when you exit from Mail or select a
    different Mail file. Otherwise, you must enter the PURGE command
    to empty your WASTEBASKET folder.

    To recover a message accidentally deleted (while it is still in
    the WASTEBASKET folder), select the WASTEBASKET folder, read the
    desired message, and enter the MOVE command to move it to another
    folder.

    Usually you delete only one mail message at a time, but you may
    also delete several mail messages at one time using one DELETE
    command. You may specify a range or a list of messages to be
    deleted.

    Format

      DELETE  [message-number][-message-number][,message-number]