Fiat means giving the payment processor significant leverage over the paid email service. Fiat also means the email service couldn't be global, because Trusted

Fiat means giving the payment processor significant leverage over the paid email service. Fiat also means the email service couldn't be global, because Trusted-Third-Party-based payment processors can't operate globally owing to the global regulatory patchwork. Contrast that with Bitcoin(Cash)-based international remittance, or Ethereum-based token sales, which are accessible to people in every country in the world. Email is an open and global protocol, so cryptocurrency is a good fit for it.