Mass. Gen. Laws ch. 183 § 27
The holder of a mortgage of real estate, or his representatives, out of the money arising from a sale under the power of sale shall be entitled to retain all sums then secured by the mortgage, whether then or thereafter payable, including all costs, charges or expenses incurred or sustained by him or them by reason of any default in the performance or observance of the condition of the mortgage or of any prior mortgage, rendering the surplus, if any, to the mortgagor, or his heirs, successors or assigns, unless otherwise stated in the mortgage. No person other than the holder of the mortgage shall be bound to see to the application of the money arising from such sale.
The holder of a mortgage of real estate, or the holders representatives, shall provide to the mortgagor or the mortgagors heirs, successors or assigns a written notice containing an itemized accounting of the disposition of the proceeds arising from a sale under the power of sale including, but not limited to, the sale price, legal fees, auctioneer fees, publication costs and other fees, and any surplus due to the mortgagor, within 60 days after the receipt of such funds provided, that if such sale is subject to further legal proceedings, such accounting shall be stayed until the conclusion of such proceedings.
Mass. Gen. Laws ch. 183, § 27