Mass. Gen. Laws ch. 244 § 17B
No action for a deficiency shall be brought after June thirtieth, nineteen hundred and forty-six by the holder of a mortgage note or other obligation secured by mortgage of real estate after a foreclosure sale by him taking place after January first, nineteen hundred and forty-six unless a notice in writing of the mortgagee's intention to foreclose the mortgage has been mailed, postage prepaid, by registered mail with return receipt requested, to the defendant sought to be charged with the deficiency at his last address then known to the mortgagee, together with a warning of liability for the deficiency, in substantially the form below, not less than twenty-one days before the date of the sale under the power in the mortgage, and an affidavit has been signed and sworn to, within thirty days after the foreclosure sale, of the mailing of such notice. A notice mailed as aforesaid shall be a sufficient notice, and such an affidavit made within the time specified shall be prima facie evidence in such action of the mailing of such notice. The notice and affidavit, respectively, shall be in substantially the following forms:
You are hereby notified, in accordance with the statute, of my intention, on or after ........, to foreclose by sale under power of sale for breach of condition, the mortgage held by me on property on ........... Street in ................ in the County of ................. dated ........ and recorded with ......... deeds Book .......... page ...... to secure a note (or other obligation) signed by you, for the whole, or part, of which you may be liable to me in case of a deficiency in the proceeds of the foreclosure sale.
I hereby certify on oath that on the ...... day of ..........(insert year) I mailed by registered mail, postage prepaid and return receipt requested, the notice, a copy of which appears below, directed to the persons or person at the addresses therein named which were the last addresses of such persons known to me at the time of mailing.
Signed and sworn to before me this ...... day of ..........(insert year)
Mass. Gen. Laws ch. 244, § 17B