Let me see if I can draw the relevant threads together into a framework
proposal that is viable to everybody:
Names should have a magic label, eg "_MARID", that is bound to the
domain name of the email address. This allows multiple RRs to be
bound to the name, and allows delegating the name.
If the name does not exist and an SOA NXDOMAIN is returned which
references a different domain than what was used in the original
query, apply "_MARID" to the SOA domain. If NXDOMAIN is returned
for that, bail. This allows leaf-nodes to have explicit entries,
and for a master entry to act as a fallback for an entire domain.
For developmental and proto-typing purposes, we should use a TXT
RR, and we should document the structure of that RR in an
informational reference spec.
We should develop a binary RR that satisfies the considerations
associated with wide-scale deployment (avoiding TCP fallback,
etc). The result of this work goes standards-track, and is the
final target for deployment.
An additional informational doc can describe coexistence and
Disucssion points beyond this approach are the structure of the textual
and binary data, the use of pointers to external policy docs, and so
forth, all of which falls into the proto-typing work item.
Eric A. Hall http://www.ehsco.com/
Internet Core Protocols http://www.oreilly.com/catalog/coreprot/