<prompt> Translate the following text to EnglishMashirika ya tatu ya kuchagua barua hukusanya barua kutoka kwa wajumbe, hukusanya na kutumia nambari za bar, na kusafirisha barua kwa Huduma ya Posta kwa sehemu ya punguzo.  <response>: These third-party sorters collect mail from mailers, sort and apply barcodes, and deliver the mail to the Postal Service for a portion of the discount. 