Repudiation

Authentication and Repudiation

• steve
• Technical

Email Authentication lets you demonstrate that you sent a particular email.
Email Repudiation is a claim that you didn’t send a particular email.
 
SPF is only for email authentication¹
DKIM is only for email authentication
DMARC is only for email repudiation
 
¹ SPF was originally intended to provide repudiation, but it didn’t work reliably enough to be useful. Nobody uses it for that now.