<prompt> Translate the following text to EnglishHuduma ya Posta ilifuata mahitaji hayo mapema mwaka wa 1973, na Mpango wa Uainishaji wa Barua za Ndani uliopendekezwa na Tume ukaanza kutumika Julai 6, 1976.  <response>: The Postal Service complied with this requirement early in 1973, and a Domestic Mail Classification Schedule recommended by the Commission became effective on July 6, 1976. 