On Fri, 3 Dec 2004, Meng Weng Wong wrote:
On Fri, Dec 03, 2004 at 05:52:06PM -0500, Stuart D. Gathman wrote:
|
| The point is to cause infinite recursion, and thereby cause mail to be
| rejected (provided client rejects on resource limit exceptions).
|
| Most implementations will give SPF pass for legit mail. The infinite
| recursion will only show up when the mail is from a spammer. A very
| unfriendly to receiver policy.
|
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.
--
Stuart D. Gathman <stuart(_at_)bmsi(_dot_)com>
Business Management Systems Inc. Phone: 703 591-0911 Fax: 703 591-6154
"Confutatis maledictis, flamis acribus addictis" - background song for
a Microsoft sponsored "Where do you want to go from here?" commercial.