libmail-spf-perl 2.9.0-4 (s390x binary) in ubuntu hirsute

 Mail::SPF is an object-oriented Perl implementation of the Sender Policy
 Framework (SPF) e-mail sender authentication system <http://www.openspf.org>.
 .
 It supports both the TXT and SPF RR types as well as both SPFv1 (v=spf1) and
 Sender ID (spf2.0) records, and it is fully compliant to RFCs 4408 and 4406.
 (It does not however implement the patented PRA address selection algorithm
 described in RFC 4407.)