[Manal]

Your IP address might be clean in all of these blacklists and checking services but major e-mail providers such as Google, Microsoft and other big players have their own internal blacklists!

This might be the case. Maybe some old customer has did some fishy stuff on the VPS? Alright then, I will try to install CWP and make an email and send it to do a test. I don't know if it is gonna end up in spam or what but I'll do it for test before I migrate my whole project to this VPS.