I did not, but usually it sends it to the post master I thought

It usually does, but unfortunately there has been a confirmed glitch with the Trials of Osiris where emblems you receive from either the chest or game rewards will not be sent to the postmaster if your emblem slots are full. Bungie has stated that they are aware of the issue, and are working to resolve it. Until then, it is best to keep an emblem slot or two open just in case.