5. Demand notice by operational creditor.—
(1) An operational creditor shall deliver to the corporate debtor, the following documents, namely.-
(b) a copy of an invoice attached with a notice in .
(2) The demand notice or the copy of the invoice demanding payment referred to in sub-section (2) of section 8 of the Code, may be delivered to the corporate debtor,
(a) at the registered office by hand, registered post or speed post with acknowledgement due; or
(b) by electronic mail service to a whole time director or designated partner or key managerial personnel, if any, of the corporate debtor.
(3) A copy of demand notice or invoice demanding payment served under this rule by an operational creditor shall also be filed with an information utility, if any.