On Saturday, August 28, 2004 at 7:56 PM, Ólafur Guðmundsson wrote (about DNS
record types):
The fundamental difference between your position and mine is
you: want everyone to be compliant at all times.
me: Specify clearly fully compliant state and tolerate non compliance
during phase-in.
This is the crux of the disagreement. However, there are at least two relevant
phase-in periods:
1. In the first phase-in, mail senders begin to publish records, and those
mail senders who need to begin to add additional headers.
2. In the second phase-in (more relevant to this discussion), people with
"challenged" DNS implementations begin to publish and/or query for the new
record type.
The problem is that the first phase-in lasts months, but the second phase-in
lasts many years. (As I mentioned previously, it's at least 10 years before the
number of installed Microsoft OS's with lousy DNS implementations becomes small
enough to ignore.)
So, given that Ólafur's "short term" isn't in fact short, my point still
stands. Require (MUST) TXT records and encourage (SHOULD) new record types.
Ólafur also worries that if we go this route, there will never be a time when
publishing only an SPF2 record becomes acceptable. This isn't necessarily so.
There are two possible futures:
a. "Challenged" DNS implementations get fixed over time, and more and more
people come to query/use SPF2 records. Eventually, a new standards action
requires the new record type and deprecates use of TXT records.
b. "Challenged" DNS implementations continue to be plentiful over time. In
this case, we'd sure look stupid of we followed Ólafur's approach.
Assuming that we go with MUST for TXT records now, I submit that a built-in
opportunity to revisit the issue is when SenderId is considered for advancement
from Proposed Standard to Draft Standard or Internet Standard. Should upgrades
to DNS servers proceed faster than the standards track, it's not hard to
convene a working group to reconsider this issue.
On Tuesday, August 31, 2004 at 1:30 PM, Mark Lentczner wrote:
I agree with Ólafur on this, since I think this document is a standard,
not a how-to manual. The How-to's and web wizards will make it clear
to people that they need to publish the TXT form for now.
The purpose of a standard is to describe the rules for interoperable
implementations. But the "MAY" in the current doc (MAY publish/query TXT
records) means that it's truly optional whether to do this. This is just wrong
-- you won't interoperate with a substantial fraction of the Internet if you
don't follow the MAY.
-- Jim Lyon