Sender Policy Framework

For certain SPF related software, openspf.org is the authoritative source. Here are official source packages for these programs. (Source code repositories for all of them are also hosted by openspf.org.)

python-postfix-policyd-spf

This is Open Patent software. Compared to the Perl policy server, this is a more fully featured solution that is much more configurable and includes various white listing options that would likely be needed for a larger scale site. It's development is ongoing. Suggestions and patches accepted on spf-devel.

This package has moved to https://launchpad.net/pypolicyd-spf/

postfix-policyd-spf-perl

This is Open Patent software. This is a basic solution suitable primarily for small scale sites. It is in maintenance only mode. If enhancements are desired, patches accepted on spf-devel. The 2.000 series uses Julian Mehnle's Mail::SPF library. It is RFC 4408 compliant. It caches results and will only prepend a single SPF Received header for multi-recipient mail. It has a basic (you have to edit the source) ability to whitelist relays and forwarders.

This package has moved to https://launchpad.net/postfix-policyd-spf-perl/

sendmail-spf-milter

1.42.1 (released 2006-07-08)

Note that the original source for sendmail-spf-milter is http://srs-socketmap.info/spf/. The revision here differs from that only in the documentation.