Reverse DNS RFCs and Recommendations

Wed Oct 30 21:45:58 UTC 2013

On Wed, Oct 30, 2013 at 8:22 PM, William Herrin <bill at herrin.us> wrote:

> > Which finally brings me to my questions:
> > It seems like the unspoken de facto that mail admins appreciate
> > given the IP 203.0.113.15 is
> > "203-0-113-15.[type].[static/dynamic].yourdomain.tld". This
> > seems perfectly acceptable, it's short, detailed and to the
> > point. Is there really anything bad about this?
>
>
> reputation services. They use this information when classifying the
> source and grouping sources into netblocks. If you take the time to
> distinguish your intended mail servers from your dialup address pool
> they'll try not to include your mail server when they ban mail
> directly from your dialup address pool.
>

At dnswl.org, we identify new servers from looking at the rDNS in what we
see is being queried through our logs. Names with "dynamic", "dialup" etc
or that look like they have an embedded IPv4 address are discarded through
that channel.

-- Matthias