Got it. We've just worked around an IPv6-related bug in *either* Google's IPv6 DNS service, named, or milter-greylist (AFAIK).
So far, it seems mostly Google users were affected.
-Adam

On July 10, 2017 7:58:24 AM CDT, John Lange <john@johnlange.ca> wrote:

Testing... If this makes it to list, please pardon the interruption.

--
Sent from my Android device with K-9 Mail. Please excuse my brevity.