Email Secretary is a Challenge/Response system designed to deter spam.
Written entirely in Perl, it is highly configurable and easy to modify.
It has a Web GUI to manage your whitelists, blacklists, and pending
messages.
Information regarding Project Releases and Project Resources. Note that the information here is a quote from Freecode.com page, and the downloads themselves may not be hosted on OSDN.
A forwarding hack was added for Exchange servers.
A problem that left stale tmp files was fixed. All
messages are queued, even if a confirmation probe
is not sent. The initial movement of unconfirmed
messages when mode = 2 was fixed.