Mass. Gen. Laws ch. 223, § 31: Summons; leaving at last known address, etc.

Section 31. In an action brought in the district court, if service is made at the last and usual place of abode, the officer making service shall forthwith mail first class a copy of the summons to such last and usual place of abode. The date of mailing and the address to which the summons was sent shall be set forth as required by section thirty-five in the officer's return.