Definitely either Ritesh himself, or one of his money mules using random forums to shift cash to Ritesh
Notice how the envelope has Ritesh written on it. On EEVBLOG forum there was a similar post with the full name Ritesh Kakkar written on the bank envelope. There was also a picture of the money mule.
There have been many posts on many forums recently, where the aim simply seems to be for each money mule to prove posting of cash.