* README

  describes the files under sample/

* sendmail-milter

  If you run sendmail, this milter will plug right in.
  You don't need to run spfd.

* sendmail-milter-with-secondaries

  This version is appropriate if your MTA serves as the
  primary MX for domains which have secondary MXes that you
  don't know about.  When a secondary MX relays mail to you,
  you want to bypass SPF checks.  This version looks at each
  recipient's domain and detects if the connecting client is
  a secondary MX.  If you don't understand what this means,
  you probably don't need this version --- use the plain
  sendmail-milter.

* exim-acl

  If you use Exim 4, this ACL will plug right in.
  You will need to run spfd for this ACL to talk to.

* postfix-policyd-spf

  If you run a recent snapshot version of Postfix, this policy
  server will plug right in.  You don't need to run spfd.

* spf.py

  Python implementation.  This may not be the latest version.
  Check http://www.wayforward.net/spf/

