- 550 error for ipv6/PTR ?

Christopher Morrow morrowc.lists at
Wed Jan 15 02:10:21 UTC 2014

On Tue, Jan 14, 2014 at 8:51 PM, Ted Cooper
<ml-nanog090304q at> wrote:
> On 15/01/14 10:06, Brandon Applegate wrote:
>> Off-list replies are fine to minimize noise, and if there is an answer
>> or any meaningful correlation I will reply on-list.  Thanks in advance
>> for any info/feedback.

brandon, I didn't get your original... but could you ping me off-list
and maybe I can get some data about what it is you're seeing? :)

> I have been running into these a lot also and have so far concluded that
> it is an error within Google. The PTR/AAAA, SPF and DKIM are all matched
> up and tested as working. It also occurring on domains using google apps
> to handle their email so it is platform wide. All of the emails are
> personal emails, but coming from multiple domains/senders.
> The exact same email will be rejected when sent to any google IPv6
> server for minutes/hours, but 3-4 hours later it will be accepted
> without error.
> The fact that it is being hard rejected is really quite annoying and
> generating a lot more support work.
> Unfortunately, my only fix at present is to turn off IPv6 delivery for
> all google hosted domains as I encounter them. It would be really nice
> if it was fixed.
> My theory is that they are failing PTR lookups.

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