why IPv6 isn't ready for prime time, SMTP edition

Brielle Bruns bruns at 2mbit.com
Wed Mar 26 02:25:57 UTC 2014

On 3/25/14, 7:58 PM, TJ wrote:
> In an attempt to get this thread back on topic:
> * Does Google require rDNS for IPv4 mail sources?

After a quick test here, Google did not reject the mail from an IPv4 
address that did not have rDNS.

> If so, doing so for IPv6 shouldn't be a surprise.  Your current provider's
> inability to support rDNS for IPv6 is not a protocol failure, it is a
> provider failure.
> If not, is there an additional operational reason for them to do so in
> IPv6?  ... and in that case, I'd come to the same end result,
> provider-failure.
> ... ?

Google willing to accept collateral damage for IPv6 mailing hosts, but 
too severe of collateral damage for IPv4 ones that would affect too many 

Like I said in a previous response, if you are going to make rdns a 
requirement, why not make SPF and DKIM mandatory as well?

Brielle Bruns
The Summit Open Source Development Group
http://www.sosdg.org    /     http://www.ahbl.org

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