Mass. Gen. Laws ch. 175B, § 2
(a) Any of the following acts in this commonwealth, effected by mail or otherwise, by an unauthorized foreign or alien insurer:
(c) Service of process in any such action, suit or proceeding shall in addition to the manner provided in subsection (b) be valid if served upon any person within this commonwealth who, in this commonwealth on behalf of such insurer, is—
1. Soliciting insurance, or
2. Making, issuing or delivering any contract of insurance, or
3. Collecting or receiving any premium, membership fee, assessment or other consideration for insurance; provided notice of such service and a copy of such process is sent within ten days thereafter by registered mail by the plaintiff or plaintiff's attorney to the defendant at the last known principal place of business of the defendant, and the defendant's receipt, or the receipt issued by the post office with which the letter is registered, showing the name of the sender of the letter and the name and address of the person to whom the letter is addressed, or if acceptance was refused by the defendant or its agent the original envelope bearing a notation by the postal authorities that receipt was refused, and the affidavit of the plaintiff or plaintiff's attorney showing a compliance herewith are filed with the clerk of the court in which such action is pending on or before the date the defendant is required to appear, or within such further time as the court may allow.