If the rental due on a safe deposit box has not been paid for one year, the lessor may send a notice by registered mail to the last known address of the lessee stating that the safe deposit box will be opened and its contents stored at the expense of the lessee unless payment of the rental is made within thirty days. If the rental is not paid within thirty days from the mailing of the notice, the box may be opened in the presence of an officer, manager or assistant manager of the lessor and of a notary public who is not a director, officer, employee or stockholder of the lessor. The contents shall be sealed in a package by the notary public who shall write on the outside the name of the lessee and the date of the opening. The notary public shall execute a certificate reciting the name of the lessee, the date of the opening of the box and a list of its contents. The certificate shall be included in the package and a copy of the certificate shall be sent by registered mail to the last known address of the lessee. The package shall then be placed in the general vaults of the lessor at a rental not exceeding the rental previously charged for the box.