Who is going to spend TIME and postage for you?

It is a big favor. Not realizing that is the biggest mistake.

Yes, (old) people with big names might be willing to support young researchers. What about those active professors and researchers you are trying to ask for? You are asking for their TIME and favor. I do not think it is natural for them to do it for a stranger no matter in what good name you fabricated -- IT IS A RECOMMENDATION based on his judgement (or evaluation in your term)!