[ietf-dkim] x= lets senders expire responsibility

[Paul Hoffman]

At 5:41 AM -0700 4/12/06, Hallam-Baker, Phillip wrote:
>I think the semantics are 'don't count on being able to verify this message
>after this date'.

Why would you think that? The semantics of x= say nothing about those 
semantics:
        Signature expiration in seconds-since-1970 format
        as an absolute date, not as a time delta from the signing
        timestamp.  Signatures MUST NOT be considered valid if the
        current time at the verifier is past the expiration date.
If you *want* the semantics to mean 'don't count on being able to 
verify this message after this date', that's fine, but you need to 
ask the WG to change the document for that to happen.