There is no messaging system; visit the user's profile (click on their name) and cross your fingers they have some kind of identifying information- an email address, a web page, etc.

You can find my email in my profile by clicking on my username.

I do see URL

     	www.localmeze.com

but I see no e-mail. When I do the same click on my Hacker News user name, then, yes, I see a line for my e-mail but the line (a text box) is empty because I haven't given my e-mail to HN.

What's going on I don't know.

I did not realize that the email is not publicly displayed. I have put in the about section now.

hn At machine.imap.cc

Just sent to

hn At machine.imap.cc