SPF tools (spfquery, spfd) based on the Mail::SPF Perl module

 A collection of Sender Policy Framework (SPF) tools that are based on the
 fully RFC-conforming Mail::SPF Perl module. The following tools are included
 in this package:
 .
   * spfquery: A command-line tool for performing SPF checks.
   * spfd: A daemon for services that perform SPF checks frequently.