Isn't there some sort of federated white list of mail domains? Something where you can just declare a domain, pay a fee, gain reputation. Aren't those free or

Isn't there some sort of federated white list of mail domains? Something where you can just declare a domain, pay a fee, gain reputation. Aren't those free or in the public domain? Something with some sort of certificates? Maybe it would also be a good solution to let users "add" an email contact or sub domain and only receive email from those, and treat unknown emails as untrustworthy.