We are in B2B business and now and then someone will send a message via our contact page with a fake name, free email, fake phone etc.
Most of the time the question itself is badly written or barely makes sense.
Is it worth bothering with these people? Do you answer all the emails or simply ignore these kind of requests?
In the end just use your judgement and you will be fine, you are already spotting those that are not worth replying to so continue to do that.