DKIM was not designed to authenticate emails far into the future. In fact, it does not authenticate any emails without a corresponding public key currently pub

DKIM was not designed to authenticate emails far into the future. In fact, it does not authenticate any emails without a corresponding public key currently published to DNS. It provides specifically for "empty" or revoked keys to avoid such retro-validation. Seems the central thesis is that because these messages are patently no longer authenticated by DKIM, we should eliminate any remaining hope of them being construed as authenticated by DKIM.