OpenDMARC is a free open source software implementation of the DMARC
specification.
The OpenDMARC project is a community effort to develop and maintain an open
source package for providing DMARC report generation and policy enforcement
services. It includes a library for handling DMARC record parsing,
a database schema and tools for aggregating and processing transaction
history to produce DMARC reports, and a filter that ties it all together
with an MTA using the milter protocol.
