<prompt> Translate the following text to EnglishKama punguzo la posta linaongezeka juu ya 4.5a, huduma ya posta inashuka chini ya breakeven na itahitaji kukamilisha hasara kwa kuongeza bei kwa wauzaji wote wa barua, wote ambao sasa wanafanya presorting na wale ambao hawajaathiriwa hadi sasa.  <response>: As the discount increases above 4.5a, the postal service falls below breakeven and will have to make up the losses with a price increase for all mailers, both those who are now presorting and those who have not thus far been affected. 