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Re: Re: DNS lookup limit?

2005-02-27 18:05:31
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).

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.

I think it's all too easy to make honest mistakes given the flexibility of SPF.

I wouldn't lobby too hard for leniency, because practically it would mean all recepients would implement the higher limit, just to avoid technical support issues.

I really can't see the point in allowing to publish 11-111
(to stay with your example).

See above how this might _accidentally_ happen.

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.

Greetings,
Radu.


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