[ipv6-ops] Re: mail filtering based on reverse DNS

[Matt Ryanczak]

On 8/11/11 11:59 AM, Aaron Hughes wrote:
> One thing I have done (which certainly does not always work) is:
>
> ; Auto respond to reverse queries with any wildcard and a zero.
> ;
> *                               		IN      PTR     v6host.ipv6.6connect.net.
> *.0                             		IN      PTR     v6host.ipv6.6connect.net.
> *.0.0                           		IN      PTR     v6host.ipv6.6connect.net.
> *.0.0.0                         		IN      PTR     v6host.ipv6.6connect.net.
> *.0.0.0.0                       		IN      PTR     v6host.ipv6.6connect.net.
> *.0.0.0.0.0                     		IN      PTR     v6host.ipv6.6connect.net.
> *.0.0.0.0.0.0                   		IN      PTR     v6host.ipv6.6connect.net.
> *.0.0.0.0.0.0.0                 		IN      PTR     v6host.ipv6.6connect.net.

I do the same. I think you showed me this trick :)

> Unfortunately, not enough people are discussing this to come up with a good solution outside of turning off reverse DNS verification. Afaik, this is going to just have to stop being used and will we should be looking into other methods of validation.

Could the solution be TLS (SMTPS)? With the rising popularity of HTTPS 
perhaps x.509 certification will catch on in SMTP.

~Matt