[ietf-dkim] Issue 1365: drop "never send mail"?

[Graham Murray]

Jon Callas <jon at callas.org> writes:

> You can say that you never send mail from a domain with SPF.

SPF operates on the RFC2181 envelope, so with SPF you can state that a
domain will never legitimately appear in the SMTP MAIL FROM: (or
EHLO). It offers no mechanism to say that the domain will not be used
in any RFC2822 From:, Sender:, Resent-From: etc