Section 15A. A mortgagee taking possession of mortgaged premises prior to foreclosure or a mortgagee conveying title to mortgaged premises pursuant to the provisions of this chapter shall, within thirty days of taking possession or conveying title, notify all residential tenants of said premises, and the office of the assessor or collector of taxes of the municipality in which the premises are located and any persons, companies, districts, commissions or other entities of any kind which provide water or sewer service to the premises, of said taking possession or conveying title.