A mortgage may be discharged by filing for record a certificate of its satisfaction executed and acknowledged by the mortgagee, the mortgagee’s personal representative, or assignee, as in the case of a conveyance. In all cases the discharge shall be entered in the reception book and indexes as conveyances are entered. If a mortgage be recorded in more than one county and discharged of record in one of them, a certified copy of such discharge may be recorded in another county with the same effect as the original. If the discharge be by marginal entry, heretofore made, such copy shall include the record of the mortgage.