Please advise how to send a private message to a forum user.
The contact button in the profile is not active
It’s not possible.
Some have an email available in profiles…
You can use non-symmetric cryptography to hand over contact information, I’ve done that successfuly more than once, e.g.: http://forum.mikrotik.com/t/question-involving-multiple-ipsec-tunnels/149132/1 .