DomainKeys Identified Mail (DKIM) and DomainKeys differ in several ways:
- DKIM offers multiple signature algorithms, while DomainKeys only offers one.
- DKIM has more options for canonicalization, which validates both header and body.
- DKIM has the ability to delegate signing to third parties.
- DKIM can self-sign the DKIM-Signature header field to protect against it being modified.
- DKIM has the ability to support signature timeouts in Domain Name System (DNS).
DKIM is the newer version of DomainKeys.
DomainKeys is outdated and not relevant to Domain-based Message Authentication, Reporting, and Conformance (DMARC) implementations.