[AusNOG] IPv6 reverse DNS and Mail ...

[Jethro Carr]

On Mon, 2013-05-20 at 19:10 -0400, David Miller wrote:
> AFAIK, there are NO "absolute and unquestionable" indicators that
> email from a source is spam, so it would be unrealistic to expect that
> reverse DNS checks meet this standard.

Not in SMTP itself, but you can go down a few layers and validate
whether or not the packets themselves are evil as per RFC 3514 and then
make a decision whether or not to accept the incoming mail request.

http://www.ietf.org/rfc/rfc3514.txt

regards,
Jethro

-- 
Jethro Carr
www.jethrocarr.com