I am not an attorney, i'm just wearing my common sense hat (although the law does not always follow common sense), but i would imagine the design etc could be copyrighted and that trying to pass it off as a different brand would be a copyright infringement.
Again, i am no attorney, but tought...
You may want to confirm this, but i believe Certified Mail is legally recognized.
I know when dealing with evictions, when you use Certified mail, the court considers it as being received 10 days after its been mailed regardless of if they received it or not. This is in AZ, and i am unsure...