Man pages matching name mail::spf::mech::exists in section 3pm:

Mail::SPF::Mech::Exists.3pm.en	debian 10 / libmail-spf-perl
Mail::SPF::Mech::Exists.3pm.en	debian 11 / libmail-spf-perl
Mail::SPF::Mech::Exists.3pm.en	debian 12 / libmail-spf-perl