Single method or choice of methods?

Hi,

I still do not see, in which main direction this discussion 
is going to. 

>From my point of view, the most important open question
(it was already raised by Raymond, but it is still not yet
answered) is:

Do we support a whole bunch of different methods
  - where the domain owner can choose which methods suit
    best for his personal requirements
  - which allow the flexibility needed to be applicable
    for most domains on the world
  - but require some plugin/library into the MTA

or do we support just a simple IP/DNS mapping
  - which might have the advantage to be implementable
    on _some_ common MTAs without plugin/library
  - might not meet most domain's requirements
  - but might find more acceptance by the owners  
    of those MTAs which allow rule based queries?


I'd definitely vote for the first approach, but 
I still see the need for discussion.

Hadmut