The voter shall sign the certification upon the inner envelope, securely seal it, enclose it in an outer serially-numbered envelope, and return it to the municipal clerk of the town in which he is qualified to vote. The clerk shall keep it in his office until delivered by him to the registrars of voters at the same time and in the same manner as is provided for absentee ballots. If the ballot is returned by a person other than the voter or the United States Postal Service, the person delivering the ballot shall sign his name and address and the date and time of its delivery on the outer envelope in the clerk’s presence. The ballot, to be cast, shall be returned so that it is received by the town clerk not later than the close of the polls on the day of the election.