Mark Andrews wrote:
It was more "the only way to prevent the A lookups is to
remove the fallback".
If we ever head down this path there would need to be years
of advance notice.
We use a "1 shot" implicit MX fallback. If we were to remove this, it
would have to be done as an option.
I have no stats on hand how much of the fallback is used among
customers, but I can say that just a few months ago while assisting my
brother, the fallback was used during the time the domain did not
propagate through the net yet. I expected it in order to get the
initial setup going for his new domain setup.
In any case, for us, I don't see any issue of making it an option
(default ON in the first few new revisions, then eventually default off)
to help in deprecating this practice.
+1 on text to deprecate the Implicit MX.
Hector Santos, CTO