Answer: mailin

AnswerCrossword Clue
MAILINKind of ballot
MAILINLike some ballots
MAILINSubmit via USPS
MAILINSubmit, as a contest entry
MAILINRebate card, e.g.
MAILINPost.
MAILINLike some questionnaires
MAILINRedeem, perhaps
MAILINKind of rebate
MAILINType of rebate
MAILINKind of campaign
MAILINSubmit via a stamped envelope
MAILINType of ballot
MAILINLike some rebates
MAILINSubmit with a stamp
MAILINLike many rebates
MAILINRemit, usually