spf-engine: spf-engine (SPF back-end) spf-engine: spf-engine: spf-engine provides the SPF (Sender Policy Framework) back-end for spf-engine: both pypolicyd-spf (for which it was originally developed) and an spf-engine: future SPF milter using pymilter. The goal is to provide a common spf-engine: back-end for common features for support SPF integration with Postfix spf-engine: and Sendmail using both the Postfix policy service and the Sendmail spf-engine: milter protocol (also available with Postfix). spf-engine: spf-engine: spf-engine: