<prompt> Translate the following text to SwahiliRate and service agreements negotiated by the Postal Service and mail users are permissible under current law if the procedural and substantive requirements of the Postal Reorganization Act are satisfied.  <response>: Mikataba ya kiwango na huduma iliyozungumziwa na Huduma ya Posta na watumiaji wa barua inaruhusiwa chini ya sheria ya sasa ikiwa mahitaji ya utaratibu na ya msingi ya Sheria ya Utaratibu wa Posta yanatimizwa. 