Hotmail tends to be quite harsh sometimes regarding to new domains or domains they don't have info about. If you really have all what you mentioned running, the only thing left is IP reputation.
For that, Microsoft has a form which will lead to a revision on their part. They will usually whitelist your domain, but that doesn't mean that initially your mails won't end up in the Spam folder of your users, they just won't get rejected.
You'll have to gain some reputation after a time, with patience and encouraging your users to click on the This is not spam button for your mails.