Mass. Gen. Laws ch. 54 § 107
The presiding officer at every polling place at elections of state and city officers and of town officers in towns where official ballots are used shall, after the record of the counting has been made, cause all ballots cast to be publicly enclosed in an envelope or container and sealed up with a seal of durable material provided therefor and also with the private seal of any election officer who may desire to affix the same. Seals for containers may be of material used in such manner as to effectively lock the container, or the container may be tied up lengthwise and crosswise with heavy twine securely tied and with the knot sealed with stationer's sealing wax. The warden and the clerk of the voting precinct, polling place or town shall endorse upon such envelope or container the polling place, the election and the date, and also a certificate that all the ballots cast by the voters of such precinct, polling place or town, and none other, are contained therein. He shall cause all ballots not cast to be enclosed in an envelope or container and sealed up as aforesaid, and shall certify on the envelope or container the contents thereof. Such presiding officer shall cause the voting lists to be enclosed in an envelope and sealed up as aforesaid and the warden and the clerk shall certify thereon to the identity of the voting lists enclosed. He shall forthwith personally deliver to the city or town clerk or transmit to him, by the police officer or constable in attendance at the election, all the ballots cast, and not cast, the voting lists, the ballot box, the ballot box seals and counting apparatus. This section shall not apply to ballots used in any approved electronic voting system which requires the transmittal of said ballots to a tabulation center.
Mass. Gen. Laws ch. 54, § 107