Man pages matching name mail::listdetector::detector::listserv in section 3pm:

Mail::ListDetector::Detector::Listserv.3pm.en	debian 10 / libmail-listdetector-perl
Mail::ListDetector::Detector::Listserv.3pm.en	debian 11 / libmail-listdetector-perl
Mail::ListDetector::Detector::Listserv.3pm.en	debian 12 / libmail-listdetector-perl