Think there's a minimum number of posts or reviews you need to have done before you can message other people direct. Sure someone can confirm.
I can confirm that you are
not correct in that statement and that the criteria for if and when any member gets PM privileges is not made public.
If it were a simple matter of number of posts the boards would be full of '+1' type posts just to get the count up.
OP
What do you want to say to someone you can't say on the main board?