Mass. Gen. Laws ch. 202, § 16: Affidavits; evidence of notice

Section 16. An affidavit of the executor, administrator, guardian or conservator, or of a person in his behalf, filed and recorded with a copy of the notice in the registry of probate, or such affidavit made by any person and filed and recorded with such copy by permission of the court upon satisfactory evidence that the notice was given as ordered, shall be admitted as evidence of the time, place and manner in which the notice was given.