This is an interface to the C library libspf2 for the purpose of testing. While it can be used as an SPF implementation, you can also use Mail::SPF, which is a little more perlish.
acquired package info from repodata DB: repodata/173a9767a6c4b91aa15d1511dc2e2deee3d57514956b3329e353b8c23cfdab4e-primary.sqlite.bz2
An implementation of the SPF specification
libspf2 is an implementation of the SPF (Sender Policy Framework) specification as found at: http://www.ietf.org/internet-drafts/draft-mengwong-spf-00.txt SPF allows email systems to check SPF DNS records and make sure that an email is authorized by the administrator of the domain name that it is coming from. This prevents email forgery, commonly used by spammers, scammers, and email viruses/worms. A lot of effort has been put into making it secure by design, and a great deal of effort has been put into the regression tests.