Here is a list of them and explanations on how they work. Which is a blend of entertainment and money earning.
https://southwestmusicservices.co.uk/pi ... 00000.html
https://helpcity.it/pipermail/esilvanio ... 00000.html
https://wimh.nl/pipermail/ameejzingcrew ... 00003.html
https://lists.uoregon.edu/pipermail/coe ... 00023.html
https://sjoen.no/pipermail/starcksjoen/ ... 00008.html
http://pssw.edu.eg/pipermail/students_p ... 00004.html
https://colorservice.it/pipermail/clien ... 00000.html
https://mediamusketiers.nl/pipermail/me ... 00003.html
https://rootsschool.edu.pk/pipermail/br ... 00024.html
https://holzbaukunst-hein.de/pipermail/ ... 00002.html
https://grafplast.pl/pipermail/lista1_g ... 00005.html
https://argeonet.pl/pipermail/mailing_a ... 00021.html