In message <8dfb9cd5-8088-02af-2245-0eaf3f96fd1b@tana.it>, Alessandro Vesely <vesely@tana.it> writes
However, IP addresses for mail seem to use ARIN networks, such as: A-YAHOO-US2 66.163.160.0-66.163.191.255, A-YAHOO-US3 209.191.64.0-209.191.127.255, ... A-YAHOO-US8 67.195.0.0-67.195.255.255, A-YAHOO-US9 98.136.0.0-98.139.255.255, ...
it depends where in the world you are.... try https://postmaster.verizonmedia.com/ which has links to (a) a complete list of relevant IPs and (b) a working link to an abuse reporting form.
RIPE's YAHOONET, 77.238.177.0-77.238.177.255, seems to be an abandoned object.
it's maintained by YAHOO-MNT so hardly "abandoned" Also you will note that the email address in NA4112-RIPE is now updated -- richard writing to inform and not as company policy "Assembly of Japanese bicycle require great peace of mind" quoted in ZAMM