libspf2 implements the Sender Policy Framework, a part of the
SPF/SRS protocol pair.
libspf2 is a library which allows email systems such as
Sendmail, Postfix, Exim, Zmailer and MS Exchange to
check SPF records and make sure that the email is authorized by
the domain name that it is coming from. This prevents email
forgery, commonly used by spammers, scammers and email