"Meng" == Meng Weng Wong <mengwong(_at_)dumbo(_dot_)pobox(_dot_)com>
writes:
Meng> In my discussions with Microsoft and AOL, I have gathered
Meng> the impression that large mail receivers favour block
Meng> records because they are more easily cached and more easily
Meng> transformed into a representation native to their internal
Meng> antispam engines. Factored records which require a new
Meng> lookup for every cache negative are, in their world, not
Meng> lightweight by comparison.
But, AIUI, CSV in it's current incarnation involves doing an SRV
lookup on the domain name; how is this more heavyweight than doing a
TXT lookup. CSV looks just as cacheable to me as SPF, but uses more
compact records...
-roy