MSFT reverse IP failure?

Christian Kuhtz chkuhtz at
Mon Feb 26 23:25:59 UTC 2018


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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