MailArchiva has a comparable feature-set to proprietary offerings. In typical open source fashion, there are a few important differences, however. The software stores emails on the filesystem directly, as opposed to using a database. Thus, it eliminates the complexity and costs associated with the management of large databases. Furthermore, emails are stored in standard RFC822 format, ensuring that archived information is accessible for the long haul.
The product utilizes the advanced search capabilities of the open source search engine, Lucene. In a matter of micro seconds, users can execute complex search queries and search through thousands of archived emails. The product also offers the capability to search inside attachments and supports many popular file formats (e.g. ms word).
MailArchiva offers a web based user interface for the search and retrieval of emails. Users are authenticated directly with Active Directory, enabling administrators to leverage their existing user accounts. Installation and configuration of the system is a breeze. It takes no longer than twenty minutes for a fresh install.
For more information on MailArchiva, visit http://openmailarchiva.sourceforge.net/"