Re: Single method or choice of methods?

[email protected] wrote:
> 
> Hi,
> 
> I still do not see, in which main direction this discussion
> is going to.
> 
> >From my point of view, the most important open question
> (it was already raised by Raymond, but it is still not yet
> answered) is:
> 
> Do we support a whole bunch of different methods
>   - where the domain owner can choose which methods suit
>     best for his personal requirements
>   - which allow the flexibility needed to be applicable
>     for most domains on the world
>   - but require some plugin/library into the MTA
> 
> or do we support just a simple IP/DNS mapping
>   - which might have the advantage to be implementable
>     on _some_ common MTAs without plugin/library
>   - might not meet most domain's requirements
>   - but might find more acceptance by the owners
>     of those MTAs which allow rule based queries?
> 
> I'd definitely vote for the first approach, but
> I still see the need for discussion.

Ultimately, both approaches end up being IP/DNS mappings. And
both will likely meet most domain owners requirements. The
question that should be asked is: "what will the server MTA
operators implement?".

For them, ease and efficiency is important. They would prefer
that the cost of supporting the acceptance of mail from roaming
users (domains) be paid for by those users (domains).

As an example:

The server MTA operator would prefer that the roaming user be
responsible for:

* Doing the DynDNS lookup to determine the user's current IP
	address.
* Updating the A RR of the domain authorization records to be
	current IP address.

For every (burst of) message(s) sent while roaming.

Rather than the server MTA be responsible for:

* Having to parse a large number of large authorization TXT RRs
	for the domain.
* Looking up the domain names from the above parsing to find
	one with the A RR matching the client IP address.


My earlier message (Subject: [asrg-rmx] Alternate bookkeeping
proposal (MVP) [was: design specifics --- the config label]),
now called Efficient Mail authorization Information Lookup (EMAIL)
in the document I'm creating, detailed a storage and lookup
methodology that IS efficient for the server MTAs, provides
the authorization expressions needed by the proposals, supports
delegations, and can use common DNS trees for common authorization
expressions.

Yes, roaming users will have to update a DNS record when their IP
address changes (they do in RMX also via DynDNS) but roaming users
_ARE_ the exception and the A RR updates can be made easy for them.


Raymond S Brand