Why do I have to change from xtramail to Yahoo?

I log into my xtramail and I get a message saying I have to register with yahoo to get my mail. So I do.... (by the way, no option for New Zealand anywhere so I had to put in fake information there - REALLY peeved me off). Now I want to know WHERE IS MY EMAIL. I know I had some email in my xtramail inbox - so where did it go. It has taken me an HOUR to register and find my way around, just to find my email GONE. What's going on???????????!!!!!11!!!!