MSFT reverse IP failure?

Ken Chase math at
Tue Feb 27 00:04:43 UTC 2018

Im not exactly sure what this is either, the client sent me a screenshot
that called itself the "microsoft connectivity analyzer", which had several
steps testing deliverability of email to their domain, with the final test
of an actual test email delivery failing.


On Mon, Feb 26, 2018 at 11:25:59PM +0000, Christian Kuhtz said:
  >A little difficult to say what this without knowing what actually is.   If this is an Azure deployment, ReverseFqdn needs to be populated on the Public IP address resource.  Please take a look here
  >-----Original Message-----
  >From: NANOG <nanog-bounces at> On Behalf Of Ken Chase
  >Sent: Monday, February 26, 2018 1:31 PM
  >To: nanog at
  >Subject: Re: MSFT reverse IP failure?
  >Having a client doing a test from the MSFT exchange tools site, which is failing.
  >NOQUEUE: reject: RCPT from unknown[]: 450 4.7.1 Client host rejected: cannot find your reverse hostname, [];
  >NetRange: -
  >CIDR: ,,
  >NetName:        MSFT
  >A bit of an oversight?
  >Ken Chase - math at Guelph Canada

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