Why is hotmail blocking my emails as junk?

All emails from my domain are being sent to the junk mail folder by hotmail. For example is blocked. The domain name has only been registered a few months and the email accounts are all new. No spam has ever been sent by them. Why are they being blocked? This is causing me a major headache!

 

Your domain name could have been registered before and marked as spam.

The server or IP addresses you host your email on have previously been spammed and are now black listed.

You are infact spamming now and their filters read and find your emails to be complete and utterly spam.

 

I've never even sent an email other than a test email from the addresses yet, so i certainly have not been spamming.