On Sun, Feb 27, 2005 at 08:05:31PM -0500, Radu Hociung wrote:
Alex van den Bogaerdt wrote:
If X = 10 and Y = 111, it would mean all recipients check the first 10.
Then just say: Everybody is required (not: expected) to have no more
than 10. Everybody is required (not: expected) to check all 10.
Precisely what I am trying to say. Thank you for putting it so clearly.
Between 10-111, it's up to the recipient if they are lenient, as the
spec does not require them to be.
This is the gray area I was talking about.
Why be lenient at all?
I think some leniency is needed because mistakes do happen, especially
since we have some indirect mechanims (mx, include, redirect).
Ack. Be lenient in terms of
"geez, these guys must have made a mistake. I'll let them know
by rejecting the message with a specific error message and won't
report them to the internet police just yet".
but don't do
"geez, these guys must have made a mistake. Let's continue
processing the record as if nothing bad happened unless it
really gets out of hand".
Say that you have a vanity domain record that references 3 MX's (#1 has
2A records, #2 has 3A records, and #3 has 2A records). This adds up to
10 queries. If any of your service providers (work, home, cottage) adds
an extra outgoing mail server, they probably won't inform you, but your
record will break.
That is correct. I'm not sure about any implications of this
(maybe the limit itself is a mistake).
I understand your point about people ending up in the gray area. I'd be
happy with no gray area; it would mean when errors like above happen,
the email doesn't become unreliable, but just breaks. A much easier to
deal with scenario.
Thanks, that is exactly my point.
Now we need to _clearly_ define other issues with these limitation.
Example: one MX lookup results in two domains, one of them having
two A records.
Without clear guidelines, interpretations of the spec could be:
- count as one (one MX lookup is done)
- count as two (MX records are a kind of indirection)
- count as three (one MX lookup is done, need to do two A lookups)
- count as one or three (depending on A records being included in
the additional section)
- maybe others?
Again, to eliminate any possible confusion, I think it is necessary
to define _exactly_ what should be counted, how and why, for any
possible scenario. Perhaps this shouldn't be in the RFC, it could
be in an implementation whitepaper.
Almost all of the discussion on this and other forums stems from
inprecise wording, uncertaincy or other kinds of confusion. I'd
really like to avoid any further uncertaincy as much as possible.
Alex