(1)Where it appears to the Postmaster-General that any post office letter box, by reason of being on the premises of any private person or otherwise, is so situate as not to afford the same security against the improper removal of postal packets therefrom or other fraud as exists in the case of other post office letter boxes, he may declare that that post office letter box shall be a private posting box, and shall affix upon or near the box a notice of its being and of the effect of its being a private posting box, and a postal packet put into that box shall not for the purpose of any enactment, law, or contract, whereby the due posting of a postal packet is evidence of the receipt thereof by the addressee, be deemed to have been duly posted.
(2)A certificate purporting to be signed by the Postmaster-General or any secretary or assistant secretary of the Post Office, and to the effect that any box or receptacle is or was provided by the permission or under the authority of the Postmaster-General for the purpose of receiving postal packets or any of them, shall in any legal proceedings be evidence of the facts stated in the certificate.