• Open source email marketing systems offer most of the same features as paid email marketing systems.email button image by Richard Kane from Fotolia.com
  
  Email marketing is popular form of online communication in which an organization or business sends electronic messages to existing and prospective customers and clients. Many companies opt to use of the many paid subscription-based email marketing systems currently on the market because they're usually easy to use and offer polished designs. But with a minor upfront investment in IT know-how, any organization can get all those same services for free by using an open source email marketing system.
  
  

PHPList

• PHPList is among the leading open source email marketing systems, with more than 10,000 new users each month. It bills itself as a "one-way email announcement delivery system" good for such uses as newsletter delivery, maintaining publicity lists and sending notifications. It can manage lists of more than 100,000 subscribers; it removes duplicates and provides a tracking system so senders can see who has received and opened the messages. Like paid systems, it also tracks what links within the message readers click on and offers templates for formatting messages. Arguably better than most paid systems, PHPList allows senders to add attachments, and developers are currently working on an email-to-fax feature.
  
  

Mailman

• Mailman is open source software for producing and managing electronic messages. Like its paid counterparts, Mailman archives messages, processes bounces, reports on delivery rates and handles spam filters. It is built on an entirely different architecture than many email marketing systems, which its developers say makes it easier to scale Mailman to larger lists, and the system is integrated with tools for discussion boards management as well. It is also compatible with UNIX-based systems.
  
  

PoMMo

• PoMMo calls itself the "The Post Modern Mass Mailer." Like other open source systems, it is software that is downloaded but managed through a Web-based interface. PoMMo includes coding to allow users to subscribe to lists through a website as well as manage standalone lists. It uses a "what you see is what you get" (WYSIWYG) HTML editor to create emails. Perhaps most distinguished by its many lists management features, poMMo allows senders to segment lists based on a number of fields, such as location or other demographics. Another mark of distinction is the ability to pause, resume and cancel messages that are being sent. Developers are working on enhanced "list hygiene" features to keep lists clean and better manage bounces.
  
  

Dada Mail

• Dada Mail, like its open source competitors, manages mailing lists, sends out mass mailings and keeps an archive of your messages. Dada is built to be integrated with the sender's Web host account. It's most known for its minimalist, keep-it-simple approach. It is allows users to subscribe themselves, and it allows senders to share messages in several different ways. For example, messages can be fed through RSS/atom feeds. It is linked to social media sites such as Twitter, and senders can make their archives public for anyone to view.
  
  

OpenEMM

• OpenEMM is one of the oldest and most sophisticated email marketing systems. Like the rest, it's for emails, newsletters and other kinds of messages, as well as bounce management, link tracking, and readership statistics. It also offers transaction- and time-triggered emails, a robust content management interface, and scripts to handle many tasks. More than 200,000 installations of OpenEMM have been tracked to date, and the system runs in Windows and Linux environments.