Re: [TechEmbedBSD] Subject format for tech-embed BSD

[SODA Noriyuki <soda%sra.co.jp@localhost>]

>>>>> On Fri, 05 Oct 2007 08:31:18 -0700,
        "H. Johnson" <misc%faradayco.com@localhost> said:

> It doesn't make sense that something in the subject line should break 
> DKIM.  Are you saying that all of the bigger lists out there are 
> "damaged"?

Yes, not all, but many lists damage DKIM signature for now.
See section 2.6.3 in the following document:
http://www.ietf.org/internet-drafts/draft-ietf-dkim-overview-05.txt

There is the following sentence there:
        List management software often makes modifications to
        messages that will break incoming signatures, such as adding
        subject tags

There is a workaround for the problem, though.
That is described in the same section as follows:
        In most cases, the list and/or its mail host SHOULD add its
        own DKIM signature to list mail.

> der Mouse wrote:
>> Only if the DKIM signature covers the Subject:.  While I'm not all that
>> familiar with DKIM, I think it has fairly fine-grained control of what
>> it signs over.

Yes, you are right.  But excluding the subject header from the DKIM
signature is discouraged.  Because spammers can add their message to
the subject header of legitimate messages which don't sign the header.
-- 
soda