<prompt> Translate the following text to SwahiliSuch systems might allow lower rates for qualifying mail, while pieces that would not qualify might be rejected or required to pay a surcharge based on costs.  <response>: Mifumo kama hiyo inaweza kuruhusu viwango vya chini kwa barua zinazostahili, wakati vipande ambavyo havitastahili vinaweza kukataliwa au kuhitajika kulipa ada ya ziada kulingana na gharama. 