Man pages matching name mail::dkim::dkpolicy in section 3pm:

Mail::DKIM::DkPolicy.3pm.en	debian 10 / libmail-dkim-perl
Mail::DKIM::DkPolicy.3pm.en	debian 11 / libmail-dkim-perl
Mail::DKIM::DkPolicy.3pm.en	debian 12 / libmail-dkim-perl