[AusNOG] Microsoft missing RDNS

[Mal]

Last couple days for sure...  but has been going longer with
40.92.62-63.0/24 for a couple weeks

Which for any decent postfix MTA configuration will cause a 554.

>
Jun 10 09:20:20 cust-mta01 postfix/smtpd[8137]: NOQUEUE: reject: RCPT
from unknown[40.92.62.80]: 554 5.7.1 Client host rejected: cannot find
your reverse hostname, [40.92.62.80]; from=<user at outlook.com>
to=<customer at domain.com.au> proto=ESMTP
helo=<AUS01-SY4-obe.outbound.protection.outlook.com>

Mal




On 11/06/2021 8:47 am, Mike Manning wrote:
>
> Hi all,
>
>  
>
> Anyone else here experiencing missing RDNS for a swath of IP’s from
> Microsoft on a few different subnets? I’ve opened a ticket with
> Microsoft netops for it and I’ve done an rDNS bypass on our local
> antispam filter however we’re now seeing o365 clients with the same
> issue when trying to receive emails from anyone with an @outlook.com
> or @msn.com email address.. where do you draw the line in adding
> bypass after bypass?
>
>  
>
> host 40.92.63.85
>
> Host 85.63.92.40.in-addr.arpa. not found: 3(NXDOMAIN)
>
>  
>
> host 40.92.62.31
>
> Host 31.62.92.40.in-addr.arpa. not found: 3(NXDOMAIN)
>
>  
>
> *Mike Manning*
> *Network Engineer*
>
> *Matilda Internet*
> ________________
>
> (Telephone +61 7 4953 0711
> (Fax +61 7 4849 5000
> 29 Gregory Street, Mackay, QLD 4740, Australia
> * Email mike at matilda.net.au
> <mailto:mike at matilda.net.au>Website www.matilda.net.au
> <http://www.matilda.net.au/>
>
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>
>  
>
>
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