All - I have just discovered that IPV6 reverse resolution for the IETF is offline. It appears to have been offline for the past 30 minutes or so. IPV6 reverse resolution is provided by Level3 - the provider at which IETF services are hosted. An emergency ticket has been opened with Level3, and has been acknowledged. They are working on the problem now. We have been assured by Level 3 that this issue has been escalated to their top engineers; however, no ETA is available yet. In the meantime, the absence of reverse DNS for IPV6 may cause some user mail servers to reject IETF mail, or to incorrectly score it as Spam. Google, for example, is currently putting all IETF mail into users' spam folders, with a warning about mail configuration. As a result, I have instructed all of our mail servers to attempt delivery over IPV4 first, before attempting IPV6 delivery, in an effort to mitigate this problem. We apologize for the inconvenience, and will send an update as soon as we hear back from Level3. Glen Glen Barney IT Director AMS (IETF Secretariat)