ned+ietf-smtp(_at_)mrochek(_dot_)com writes:
Let the discussion begin...
It strikes me that many senders will want to pick at most one category,
which requires receivers to add the entire IANA registry in the SMTP
server configuration in order to avoid spam. That's not fortunate.
Hi Arnt -
Good comment. I hope that's not a huge issue ... one purpose of a
designated expert is to try and reduce the number of registrations
to something manageable. Note also the trailing wildcard provision
as a second mechanism to reduce the registry size.
In term of the EHLO command, you are correct you need to load and
dump if you want a blanket "I don't want anything." In practice,
I would think most implementations would allow users to load
"what matters" (e.g., the most common half-dozen), then perhaps
log unknown keywords as they come across the wire, allowing users
to add new classes as they become common.
I think the classes you'll see in a Solicitation: header will be
very few ... it takes forever to pass a law. You'll find more
in the received: headers, but you'll probably only care about
the ones your particular filtering software uses.
If people think this is an issue, there's a couple of things we
could do. The easiest would be a machine-readable (e.g., xml)
registry that could be retrieved at install, run-time, or when
the user reads mail. I purposely didn't spec that in as that
isn't how the IANA currently maintains registries and, rather
than push that particular envelope, it seemed easier to allow
developers to decide how they want to handle that in practice.
Regards,
Carl