> > > > I'm not sure about HELOs that are IPs. How many legit email would be
> > > > blocked by that?
> > > a lot - and several listservs I saw (running lsoft listserv) even helo as an
> > > RFC1918 IP. :(
> > > pity - it makes excellent filter fodder otherwise.
> > What's an RFC 1918 IP?
>
> 1918 Address Allocation for Private Internets. Y. Rekhter, B.
> Moskowitz, D. Karrenberg, G. J. de Groot, E. Lear. February 1996.
> (Format: TXT=22270 bytes) (Obsoletes RFC1627, RFC1597) (Also BCP0005)
> (Status: BEST CURRENT PRACTICE)
>
> Anything in 10.0.0.0/8, 172.16.0.0/12 or 192.168.0.0/16
I see. I can think of a few others that aren't valid.
0.0.0.0/7, 2.0.0.0/8, 240.0.0.0/4 off the top of my head.