DKIM and DomainKey signatures

[Bron Gondwana]

On Wed, Jan 06, 2010 at 12:35:00PM -0500, Ken Murchison wrote:
> Bron Gondwana wrote:
> >Hi all,
> >
> >Any objection to adding this?
> >
> >+    /* signatures tend to be large, and are useless without the body */
> >+    { "dkim-signature", BIT32_MAX },
> >+    { "domainkey-signature", BIT32_MAX },
> >+
> 
> I added these, along with domainkey-x509

Thanks.

We've actually added a handfull of x-* headers locally now to support
faster display of a bunch of spam status things.

    /* for efficient FastMail interface display */
    { "x-spam-score", 3 },
    { "x-spam-hits", 3 },
    { "x-spam-source", 3 },
    { "x-resolved-to", 3 },
    { "x-delivered-to", 3 },
    { "x-mail-from", 3 },
    { "x-truedomain", 3 },
    { "x-truedomain-dkim", 3 },
    { "x-truedomain-spf", 3 },
    { "x-truedomain-domain", 3 },

Which all works fine, except if Cyrus ever gets any more headers added
upstream, we can't just merge the code directly without reconstructing
every mailbox!  I'm not sure what can be done about that efficiently.
I know dovecot does some sort of a "dynamic caching" based on headers
that are frequently requested, but I'm not sure we need that - just the
ability for sites to list which headers they want cached in addition to
the defaults without being incompatible with future upgrades.  It might
require splitting CACHE_MINOR_VERSION in half and having half for
upstream and half for local or something though... messy.

Bron.