I just setup wpmu under blog folder. Everything is running smoothly until the first user tries to register. Every register steps are confirmed, but he can not get any activation email, while as the blog creator, I initially get the activation email. I do not have any clue of that. I tried to add the user at the admin panel, it works out functionally. The user can get the email from the system. I don't why this thing happened. It is so weird. Any thoughts? I really appreciate any of your following inputs.