On Sat, 4 Dec 2004, Stuart D. Gathman wrote:
On Sat, 4 Dec 2004, Stuart D. Gathman wrote:
i'm not sure what the practical problem is with infinite
recursion. loop detection is trivial and all spf
implementations i know of implement it.
The problem is it makes you do 20 (or whatever your limit is) DNS lookups
instead of 1 or 2. I.e., it wastes the receivers resources.
The waste can be significant if the domain is commonly spammed.
Duh - Meng meant that good implementations would not hit the recursion
limit because they have loop detection, and would stop after the 2nd level.
And further, the repetition is somewhat cheap assuming the mta is close to
a dns cache.
--
Terry Fielder
Manager Software Development and Deployment
Great Gulf Homes / Ashton Woods Homes
terry(_at_)greatgulfhomes(_dot_)com
Fax (416) 441-9085