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Re: 3028bis, section 4.2, paragraph 2

2007-02-08 22:16:16

On Thu, 8 Feb 2007, Tim Showalter wrote:
Mark E. Mallett wrote:
So it sounds like you are saying that the new text about how the count
of Received headers MUST be larger is connected to that.  That since
some implementations may choose to count Received lines to avoid loops,
all implementations must have a higher Received line count when doing
redirect.

Yes. That seemed to be the list concensus, based on the thread with subject "Comments on draft-ietf-sieve-3028bis-09 from Eric Rescorla" at the beginning of November. I didn't see any one arguing against mandating the addition of Received header fields by 'redirect' back then, so I took it to be agreed.


If two (or more) implementations are configured to loop, just one adds Received headers and uses them for loop control, that's enough to stop the loop.

Yes, but if just one implementation (in the "code base" sense) does _not_ add Received header fields and it is installed at multiple site, then it can sustain a loop. Heck, an implementation with no loop control can be a mailbomb generator if it supports multiple redirects for a single message: it would just a sieve script that redirects to its own address as well as the victim address.


I can't imagine why anyone wouldn't add Received anyway, just based on advice in 2821 (and common sense).

Common sense is as common as a sense of humor, apparently. (References to solving the Halting Problem were removed from 3028bis after multiple reviewers expressed their dislike for the text.)


Philip Guenther

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