Modern milter for SPF checking

 pyspf-milter is a full featured milter for SPF checking. It includes a
 variety of whitelisting mechanisms and policy options to enable it to
 support the widest variety of system requirements. It is implemented in pure
 Python and uses the python-spf module. The SPF web site is
 http://www.openspf.net/. It has been updated to support RFC 7208.