E-mail can be preferable to telephone communication in several important ways. Once the system is set up, it costs virtually nothing to send a message. And the user can attach to an e-mail message and transmit all kind of electronic file with little difficulty.

E-mail can also be preferable to fax communication for certain purposes. It is often more legible. It is also harder to misroute, since most of it is sent to verified addresses that the sender can select from an electronic address file.

E-mail can even supplement courier services, since even 1000-page documents in proper electronic form can be sent out by e-mail.

Letters obviously provide a permanent record of transactions and communications, and paper correspondence is still the most relible means of keeping and filing records at both ends of a correspondence. Letters and other paper documents may be essential both as reminders and for establishing obligation and responsibility, and a signiture may needed to validate a document. However, e-mail messages that are printed out become just as permanent and for many purposes just as valid, as letters sent in normal ways.