An electronic messaging system for both participating institutions and nonparticpating institutions and their populations. When an institution is participating in the system of the present invention, both message senders and recipients are authenticated and known and verified before any communication can take place. Messages for institutions not currently participating in the system are converted to printed mail for delivery to the non-participating institution using traditional postal systems. The present invention also teaches novel message processing techniques that take advantage of the electronic format of the messages to provide automated security and translation and/or transliteration services and further teaches the novel feature of marking incoming messages with a code to assist in accurately and secure delivery of reply messages to the appropriate party.