Sending banks online letters (the converse of online statements)

Banks, utility companies, etc have been pushing their customers towards online statements, as they save the companies money (together with being good the for the environment). But this has principally been a one-sided relationship. There is an opportunity for these companies to provide a secure communications medium (similar to email) on their online systems. As the user has to log in to be able to access and send messages, concerns over private financial details are negated. Such a system should include the ability to send attachments to the company, e.g. scanned receipts.