||A DKIM_DNSSEC is a mnemonic describing the security
of a key record acquired via the DNS.
- DKIM_DNSSEC_UNKNOWN -- DNSSEC evaluation not done
- DKIM_DNSSEC_BOGUS -- DNS response failed DNSSEC evaluation
- DKIM_DNSSEC_INSECURE -- DNS response was not secured by DNSSEC
- DKIM_DNSSEC_SECURE -- DNS response was secured by DNSSEC