research process - Unsolicited request for a scientific collaboration

I have a research problem in an area of Mathematics. There is mathematician whose domain of expertise is very near to the subject of my problem.

I read frequently his works, he probably doesn't know me. But it is possible that he has seen some of my works. He is a senior mathematician. I am junior.

Anyway we don't know each other and because of geographical and other considerations, I don't think we have the occasion to meet each other in a conference or workshop in new future. I am scientifically isolated in my country as nobody works in my area, finding funds for participating in conferences and workshops is also very difficult. So the only possibility of a collaboration that I envisage is doing by email.

I am very optimistic that my problem interests him and if we collaborate, the result would be very fruitful. I have had some experiences to do scientific collaboration with some people that I knew by email. But the story with this mathematician is different because we don't know each other personally.

I feel that sending an email saying that my name is X and I am interested in the question Y, I would be glad if you are interested to work on this problem is not perhaps the best approach.

What is the best strategy to maximize the chance of starting a scientific collaboration with him? How I can formulate my request of doing a scientific collaboration with him? Is it wise to 'reveal' my problem while I don't know if there is a chance of collaboration?