Support <surgemailHIDDEN@t@netwinsite.com> wrote:
>Is there really any such email server ? I am curious why anyone would do that for any >real reason other than to test things, how odd...

It is not likely that there are any production IPv6 only networks in the US;  I don't believe, by choice,  as there are too many networks not V6 enabled yet.   However, my understanding is there are networks in  APNIC region, where the only addressing available is IPv6.

And  IETF made the advisory through proposed standard  rfc6540  http://tools.ietf.org/html/rfc6540   S.2  clarifications; that V6 is no longer considered optional for new IP network deployments,

"*New IP implementations must support IPv6."
"* New and updated IP networking implementations should support IPv4  and IPv6 coexistence (dual-stack), but must not require IPv4 for proper and complete function."

"*Implementers are encouraged to update existing hardware and software to enable IPv6 wherever technically feasible."



>ChrisP.
--
-Jimmy