Electronic Mail

Electronic mail services work by storing messages created by some
users until they are retrieved by their intended recipients.

The ingredients of a typical system are: registration/logging on
facilities, storage, search and retrieval, networking, timing and
billing. Electronic mail is an easy add-on to most mainframe
installations, but in recent years various organisations have sought
to market services to individuals, companies and industries where
electronic mail was the main purpose of the system, not an add-on.

The system software in widest use is that of ITI-Dialcom; it's the
one that runs Telecom Gold. Another successful package is that used
in the UK and USA by Easylink, which is supported by Cable & Wireless
and Western Union.
In the Dialcom/Telecom Gold service, the assumption is made that
most users will want to concentrate on a relatively narrow range of
correspondents. Accordingly, the way it is sold is as a series of
systems, each run by a 'manager': someone within a company. The
'manager' is the only person who has direct contact with the
electronic mail owner and he in turn is responsible for bringing
individual users on to his 'system' -- he can issue 'mailboxes'
direct, determine tariff levels, put up general messages. In most
other services, every user has a direct relationship with the
electronic mail company.
The services vary according to their tariff structures and levels;
and also in the additional facilities: some offer bi-directional
interfaces to telex; and some contain electronic magazines, a little
like videotex.
The basic systems tend to be quite robust and hacking is mainly
concentrated on second-guessing users IDs. Many of the systems have
now sought to increase security by insisting on passwords of a
certain length--and by giving users only three or four attempts at
logging on before closing down the line. But increasingly their
customers are using PCs and special software to automate logging-in.
The software packages of course have the IDs nicely pre-stored....