Our first inbound email via IPv6 (was spam!)

[raymond at prolocation.net (Raymond Dijkxhoorn)]

Hi!

> In preparation for the World IPv6 Launch, inbound (SMTP) email to the
> comcast.net domain was IPv6-enabled today, June 5, 2012, at 9:34 UTC.
> Roughly one minute later, at 9:35:30 UTC we received our first
> inbound email over IPv6 from 2001:4ba0:fff4:1c::2. That first bit of mail
> was spam, and was caught by our Cloudmark messaging anti-abuse platform
> (the sender attempted a range of standard spam tactics in subsequent
> connections).
>
> In the past several hours we have of course seen other messages from a
> range of hosts, many of which were legitimate email ? so it wasn't just
> spam! ;-)
>
> Since the Internet is of course more than just the web, we encourage
> others to start making non-HTTP services available via IPv6 as well.

Looking more closely... Is this still work in progress?

;; ANSWER SECTION:
comcast.net.            358     IN      MX      5 mx3.comcast.net.
comcast.net.            358     IN      MX      10 mx1.comcast.net.
comcast.net.            358     IN      MX      5 mx2.comcast.net.

;; ADDITIONAL SECTION:
mx2.comcast.net.        6958    IN      A       76.96.30.116
mx3.comcast.net.        358     IN      A       68.87.26.147
mx1.comcast.net.        358     IN      AAAA    2001:558:fe14:70::22

You are now only accepting IPv6 if all IPv4 fails?
Or will AAAA records for mx2 and mx3 added later?

Bye,
Raymond.