Need for private messaging
I think it would be a really good idea if each user had the option to send private messages to one another. While the obvious workaround is to just post our email addresses in whatever discussion we are currently involved in, I don't care for publicly posting that bit of personal info. Furthermore, the option of private messages might help to avoid those long posting chains where one person begins a topic, and then several others hijack it with problems of their own (example: https://www.cfd-online.com/Forums/fluent/62766-how-generate-wave-fluent.html). In my opinion, this is very frustrating if you are trying to read through the post to find the particular solution to your problem.