How to send a private message to another Unity Answers user?

Everything is in the title. I don’t have access to other user’s mail address. So, How can I send messages to other users?

You can’t! This is not another social platform, it’s a knowledge base. Questions posted here should be “of interest to at least one other Unity user somewhere”. Personal contact would bypass the community. This site is more like wikipedia. Personal or subjective questions don’t belong to thie site. Use the forum instead.

This is ridiculous.
What if I’m very interested in someone’s work and want to cooperate with him???