Interesting history and analysis of SMTP’s history. How can we prevent fedi and other open protocols from suffering the same fates?
5 points
You need to set up dkim to prevent spoofing. Each message sent has a digital signature that matches one on a DNS record for your domain. You can also set an SPF record, which will tell the recipient what up addresses are authorized to send mail on behalf of your domain.
The recipent must have policies in place that reject mail which fails dkim/spf
