[ietf-dkim] Concerns about DKIM and mailiing lists, etc.

[Paul Hoffman]

At 2:05 PM -0800 3/15/06, Michael Thomas wrote:
>And then what? What would you have my receiver do differently just
>because some random third party inserted a signature?

There is no "random third party" here. It is a mailer that the user 
gets mail from. The signature would match the content of the message 
that they got, including list-specific content such as List-* 
headers, the possibly-munged Subject line, and the possibly-munged 
body.

What they would do differently is validate the signature, see that it 
is from someone who is supposed to be signing the message, and accept 
it, just like they do for regular mail.

>In any case, we're only talking about
>one valid signature since the mailing list torqued the original signature.

If there is WG agreement that there can only be one DKIM signature 
per message, then the mailing list removes the existing signature and 
replaces it with its own. If there is WG agreement that there can be 
parallel or cascading signatures, then the mailing list adds its 
signature.

The fact that the WG has not yet decided how to handle multiple 
signatures does not mean that it won't in the future.