The utility of email-based communications in an enterprise is beyond question. With innovative uses such as monitoring critical systems via email alerts, group communications via carbon copy, and mailing lists, email has been and will continue to be the main application for enterprise-wide collaboration. Here we cover open source email server solutions, mailing list managers, and software that facilitate collaboration.
From the very first one sent on Arpanet in 1971 to the billions sent today, email forms the heart of modern electronic communications. The growth of email use follows closely the growth of Internet use in general. As a result, virtually all Internet users rely on email. Early email use was entirely text based, with HTML email gaining prominence in the 1990s.
Graphical email clients appeared in the early 1990s and were a huge success because they made email easier to use. Microsoft Outlook quickly gained a majority of the market share for enterprise use after its first release in 1997. It displaced Eudora and other email clients, because of its superior graphical user interface and its approach to combining email with personal information management activities such as calendaring. Open source graphical clients, such as Novell Evolution and Mozilla Thunderbird, have been steadily gaining ground on Outlook, and they are now ready for prime-time use.
On the email server front, Microsoft Exchange is the dominant player in the enterprise, especially since Exchange Version 2000, which improved greatly upon earlier versions. Outside of big enterprises, open source email servers such as Sendmail, Postfix, and Exim dominate the landscape. Open source email servers lost ground to Exchange, because Exchange offers a comprehensive solution that meets an enterprise’s email needs. This reduced the overhead for manageability significantly and made Exchange an attractive option for enterprises. However, with the proliferation of viruses and spam in recent years, coupled with Exchange’s inability to keep up with the challenges posed, open source email servers are once again a viable alternative. While no one open source project is a “drop-in” replacement for Exchange, it is certainly possible to assemble a solution from open source parts. Furthermore, various open source products can be used effectively in conjunction with Exchange.
In this appendix, we will look at the four major product categories of open source email projects: client, server, antispam and antivirus, and mailing list managers.