A system and method for leveraging email to complete a checkout for registered and unregistered customers of the e-commerce system are disclosed. The system and method include receiving, by an email payment gateway, an email message comprising a customer email address and a token. The token includes transaction information for a transaction from a third party vendor. The system and method further include determining a registration status of a customer based on the customer email address, wherein the registration status is one of a registered customer of the e-commerce system or an unregistered customer of the e-commerce system. The system and method further include decoding the token and sending an email message to the customer email address based on the registration status and the decoded token.