Dave Crocker wrote:
I think you hit the nail on the head. Some common way for the recipient to
know which of (CSV, SPF, DomainKeys, etc, etc) is available would be nice.
Otherwise, the recipient is left "hunting", ie, searching all places it
knows about, on DNS or wherever.
What MIME types does a recipient support?
What servers does a target host support?
With extremely few exceptions, Internet mechanisms do not support a
test-before-using model.
If I read your reply correctly, you would support such an initiative
which would advertise what else is available.
I think what I call 'hunting' you call 'test-before-using' ?
In fact, for SPF I would suggest we set aside a whole modifer set for
this purpose. Perhaps the modifiers that start with the character "o"
can be used to designate "other" mechanisms. Ie o{mechanism}=
That way, future mechanisms won't collide with existing modifiers.
So opra=_pra and omfrom=_from might be two representations.
I would stay away from allowing SPF-specific macros, such as in
opra=_pra.%{d}.
This way, even if a domain implements some other, non-SPF compatible
method, it can still look for the simple string "oXXX=.*" and recognize
what it is looking for, without having to understand the SPF-specific
syntax of "%{d}"
Radu.