No, the idea is that users would be able to set an incoming fee per email address, including a default fee for unknowns. Users would simply whitelist email sub

No, the idea is that users would be able to set an incoming fee per email address, including a default fee for unknowns. Users would simply whitelist email subscriptions at 0 fee. In fact, this could likely be done completely automatically beyond the initial setup (and then only if you want to diverse from the defaults).