Startup Idea : Absolutly spam free mailbox

Message/email service. You can be contacted only by people from your contact list. If user have not you contact, system send you notification, that some one try to contact you. You decide to add him/her to you contact list and after that you will receive message. Newsletter plugin included. Any time you can subscribe or unsubscribe any newsletters. You exactly know, who has your contact. Additionally you can create one-time-use adresses. Accent on the biggest simplicity as possible. No more spam.