/usr/share/perl5/Mail/SPF/ is in libmail-spf-perl 2.9.0-4.
This file is owned by root:root, with mode 0o755.
..
/usr/share/perl5/Mail/SPF/Base.pm
/usr/share/perl5/Mail/SPF/Exception.pm
/usr/share/perl5/Mail/SPF/MacroString.pm
/usr/share/perl5/Mail/SPF/Mech/
/usr/share/perl5/Mail/SPF/Mech.pm
/usr/share/perl5/Mail/SPF/Mech/A.pm
/usr/share/perl5/Mail/SPF/Mech/All.pm
/usr/share/perl5/Mail/SPF/Mech/Exists.pm
/usr/share/perl5/Mail/SPF/Mech/IP4.pm
/usr/share/perl5/Mail/SPF/Mech/IP6.pm
/usr/share/perl5/Mail/SPF/Mech/Include.pm
/usr/share/perl5/Mail/SPF/Mech/MX.pm
/usr/share/perl5/Mail/SPF/Mech/PTR.pm
/usr/share/perl5/Mail/SPF/Mod/
/usr/share/perl5/Mail/SPF/Mod.pm
/usr/share/perl5/Mail/SPF/Mod/Exp.pm
/usr/share/perl5/Mail/SPF/Mod/Redirect.pm
/usr/share/perl5/Mail/SPF/Record.pm
/usr/share/perl5/Mail/SPF/Request.pm
/usr/share/perl5/Mail/SPF/Result.pm
/usr/share/perl5/Mail/SPF/SenderIPAddrMech.pm
/usr/share/perl5/Mail/SPF/Server.pm
/usr/share/perl5/Mail/SPF/Term.pm
/usr/share/perl5/Mail/SPF/Util.pm
/usr/share/perl5/Mail/SPF/v1/
/usr/share/perl5/Mail/SPF/v1/Record.pm
/usr/share/perl5/Mail/SPF/v2/
/usr/share/perl5/Mail/SPF/v2/Record.pm