posthouse

noun

1. A company that carries out post-production.

   “Slow motion, fades, wipes, and text — once only affordable for major broadcasters and posthouses — now allowed DIY video producers a more polished, professional look.”

2. (historical)A house at a staging post: an inn with a stable where relays of horses could be changed, for stagecoaches or the mails.

   “At each mile there are little guardhouses, where a policeman is stationed; and there is a wooden gong, which by means of concerted signals may be made to convey information over the country with great rapidity. About every six or seven miles is the post-house, where the horses are changed as quickly as were those of the mail in the old coaching days in England.”

3. (obsolete)A building for distributing mail; a post office.