The cryptographic algorithm and key size requirements included when DomainKeys Identified Mail (DKIM) was designed a decade ago are functionally obsolete and in need of immediate revision. This document updates DKIM requirements to those minimally suitable for operation with currently specified algorithms.| IETF Datatracker
How We Cracked a 512-Bit DKIM Key for Less Than $8 in the Cloud| dmarcchecker.app