This command is used to invoke a mailbox which is a kind of "notice board" used to broadcast messages under Natural Security. The contents and/or expiration date of the mailbox can be modified.

MAIL If you enter the MAIL command without any parameters, a window is displayed prompting you to enter a mailbox ID.
MAIL * A list of all mailboxes you may use is displayed, and you may then select a mailbox from the list.
MAIL mailbox-id If you specify a mailbox-id (maximum 8 characters), the corresponding mailbox is invoked directly. The mailbox-id must have been defined in Natural Security.

For further information, see Mailboxes in the Natural Security documentation.