Harry Katz writes:
Splitting off another further different topic.
If I understand section 6.1 of the SPF spec correctly, an SPF receiver
must abort evaluation if any unrecognized mechanisms are encountered.
...
In effect sending domains have to wait until substantially all
receiving domains have upgraded their software to support the new
mechanism -- and how would they know this? -- until they add the new
mechanism to their SPF record.
The same would seem to be true for infrequently used/supported features.
If, say, exchange or sendmail ships an incomplete spf implementation
that lacks macro support, wouldn't that prevent most SPF sites from
using macros, and permit more implementations from shipping without
macros, in turn encouraging more sites to do without macros, etc, etc?
Pragmatically speaking, this means that no new SPF mechanisms will be
successfully introduced ever. I'm curious why this approach was
taken.
AOL.
Arnt