Secondly, as for the authenticity of these cooperation or letters, we really need to be vigilant. As long as we need the patentee to pay or transfer the patent right in advance, we can refuse. Such cooperation plans are usually deceptive. Generally speaking, even if you cooperate, you should take the initiative. For example, when transferring, we need to wait until the other party's money has been transferred, and then go through the patent transfer procedures.
Generally speaking, if our patented technology is not a breakthrough invention, there is usually little chance that the door-to-door cooperation scheme is a very good thing. We'd better take the initiative if we want patents to play a greater role. The above comments are for reference only.