Prevent spoofing and phishing with DMARC (Google Support Infos)
DMARC DKIM SPF compliance which allows us to know who (which domain, which IP address) is usurping our identity (our domain name) and valid messages/domains/IP address.
Mail server : mail.zw3b.eu
158.69.126.137
| 2607:5300:60:9389:17:4:0:1
| 2607:5300:60:9389:17:4c1:0:1a
And above all, could a competent authority verify the IP addresses of usurpers ? Should I add "and sanction them" or am I to do it ? Thanking you !