Systems and methods for providing user-confirmation of an electronic transaction and in particular, protocols for enabling electronic signatures and confirmation of electronic documents and transactions such as electronic financial transactions and credit card payment. In one aspect, a method for confirming an electronic transaction, comprises the steps of: performing an electronic transaction between a first party and a second party; sending, by the second party, a request for confirmation of the electronic transaction to a predetermined, private mailbox associated with the first party; accessing the private mailbox by the first party; and sending, by the first party, a reply message to the request for confirmation to thereby confirm authorization of the electronic transaction.