Dialcom Inc. was a United States corporation which developed the world's first commercial electronic mail service. It was founded in 1970 by Robert F. Ryan and was sold to ITT Corporation in 1982, becoming ITT Dialcom. Dialcom's e-mail software ran on Prime minicomputers and was licensed to governmental telecommunications providers in over seventeen countries. Various extra features could be offered by Dialcom-based services, including gateways to telex and fax, and online information retrieval services. In 1986, British Telecom, who used Dialcom software for its Telecom Gold service, bought Dialcom from ITT.
Each Dialcom system was allocated a two-digit identification number. This was used as a prefix for the Dialcom e-mail addresses (or "mailboxes"), thus allowing e-mail to be exchanged between difference Dialcom services. By 1990, the following Dialcom systems were operating:
Dialcom began as computer time-sharing services. A user would sign on using an Teletype Model 33 ASR and a modem with acoustic coupler, running at 110 bps. A command-line interface was available with programming languages such as BASIC and Fortran. The Company grew and evolved quickly over a four-year period through a series of acquisitions led by Robert F. Ryan, Founder, President and CEO. By 1974 Dialcom was nationwide and offering a number of "off the shelf" products such as accounting and payroll services. Dialcom "reinvented" itself about every four years by coming out with a completely new product line (all related though the thread of telecommunications) to become the dominant leader in whichever area it targeted, while still supporting and growing the prior underlying services. In 1974 Dialcom developed an online word processing and document management suite of products. For one of its major clients, the US House of Representatives, Dialcom supplied a total constituent management system (CRS) to 240 of the 435 House offices. This service was also marketed to associations and large corporations. Four years later Dialcom developed and successfully marketed the first commercial email service in the US and then went international with that service. Mr. Ryan was the sole marketer and negotiator for all international sales that were done at the Ministerial level in each country. In keeping with the corporate philosophy of constant innovation and evolution, during 1980 Dialcom was the creator, designer, developer, computing and network engine of "The Source".