(iv) mailing it to the appropriate city or town clerk.
All early voting ballots submitted by mail, delivered in person to the office of the city or town clerk, returned to a secured municipal drop box for the city or town where the voter is registered or returned electronically pursuant to the accommodations granted to a voter by reason of disability under paragraph (4) shall be received by the city or town clerk before the hour fixed for closing the polls on the day of a preliminary, primary or election; provided, however, that an early voting ballot mailed on or before the day of a biennial state election shall be accepted until 5 p.m. on the third day after the election and shall be processed in accordance with section 95. A postmark, if legible, shall be evidence of the time of mailing.