What are the differences between DomainKeys (DK) and DKIM?
1. DKIM is the successor to Yahoo DomainKeys.
2. DKIM supports signature timeouts in DNS.
3. DKIM allows third parties to sign.
4. DKIM has additional aspects of Cisco's Identified Internet Mail standard (IIM).
5. The enhancements to this standard give more security and flexibility then DomainKeys alone.
6. DKIM allows for multiple signature algorithms while DK only allows one.
7. DKIM allows for multiple signature algorithms (DK only allows one)
8. DKIM has more options that would allow you to validate both the header and body.
9. DKIM allows self-sign the DKIM-Signature header field (helps protect against modification)
10. DKIM gives you the option to use a wildcard on some parameters.