1) Big catalog company expense 2) Charge 3) Charge for delivering mail 4) Charge for sending mail 5) Indicia 6) It may be due 7) It may get a licking 8) Letter delivery fee 9) Lima expense 10) Mail fee 11) Mail necessity 12) Mail-order expense 13) Mailing charge 14) Mailing fee 15) Pitney-Bowes meter filler Found on https://www.crosswordclues.com/clue/postage
Post'age noun The price established by law to be paid for the conveyance of a letter or other mailable matter by a public post. Postage stamp , a government stamp required to be put upon articles sent by mail in payment of the postage, esp. an adhesive stamp issued and sold for that purpose. Found on http://www.encyclo.co.uk/webster/P/133