The Libelle Mail Archive provides:
This is an archival mail storage and search tool that has been designed for SME and private use. All mail passing through your mail server, both inbound and outbound, is captured, indexed by date, subject, sender and recipients and stored in a central database. The archive can be searched and selected mail messages retrieved by a fast, easy-to-use graphical search tool which can be installed on any or all of your PCs.
The Libelle Mail Archive is designed to co-operate with the Spamassassin mail filter. By default it does not store mail that Spamassassin has marked as spam though this check can be overridden. Conversely, Spamassassin can use the Libelle Mail Archive plugin to automatically whitelist people who have previously received mail from you.
The Libelle Mail Archive is designed to minimise maintenance effort. During normal operation this consists of no more than regular back ups. The PostgresQL database was selected to hold the archive for its maturity, reliability and ability to manage itself without needing administrative attention. Libelle Mail Archive is implemented in Java 6 for robustness and platform independence: no components are reliant on any platform-specific features, though the local mail server must be capable of making a blind copy of all traffic. It was developed and extensively tested using the BCC feed provided by Postfix.