The AmavisNewSQL SquirrelMail plugin gives you
per-user control of a subset of SpamAssassin
settings which are stored in a database. It also
allows you to use a quarantine database for
questionable mail. This plugin was designed with
enterprise use in mind, and differs from other plugins in that it works with amavis-new
rather than SpamAssassin directly. Most of the
code lives in an external class that you can reuse
in your own admin tools. It even has support for
SOAP calls to perform common tasks.