administrivia: reasons for Guy's problem

[Richard Welty <rwelty@domain.elided>]

[despite the lack of any direct stag content, i'm sending this to the stag
list as the technical issues may affect many members of the lists over
time. this message is phrased as information for Guy -- rpw]

in perusing the headers in your message, i saw two mail relays involved in
getting it out to the world:

Received: from uranus.energy.com.au (sydelec.energy.com.au [163.8.6.101])
by flametree.energy.com.au (AIX4.2/UCB 8.7/8.7) with SMTP id IAA42354 for
<majordomo@domain.elided>; Tue, 21 Jul 1998 08:37:16 +1000 (EET)

sydelec.energy.com.au
flametree.energy.com.au

sydelec is given an ip address of 163.8.6.101; no ip address is recorded
for flametree. if i do a lookup in the domain name system, i get the same
ip (163.8.6.101) for sydelec, and i get an ip of 203.63.135.21 for flametree.

the problem is that the reverse lookups don't work. i should be able to run
the lookup program (nslookup on unix systems), enter the ip address, and
get the actual domain name of the host back.  if i attempt to look up
either of these ip addresses in the domain name system, i get the following:

$ nslookup
Default Server:  ns1.krusty-motorsports.com
Address:  192.94.170.7

> set type=ptr
> 163.8.6.101
Server:  ns1.krusty-motorsports.com
Address:  192.94.170.7

*** ns1.krusty-motorsports.com can't find 101.6.8.163.in-addr.arpa.:
Non-existent host/domain
> 203.63.135.21
Server:  ns1.krusty-motorsports.com
Address:  192.94.170.7

*** ns1.krusty-motorsports.com can't find 21.135.63.203.in-addr.arpa.:
Non-existent host/domain
> 

the issue is that krusty is configured to refuse mail from hosts whose ip
addresses don't have properly configured reverse lookups. this is a
configuration problem in the energy.com.au domain that your sysadmins need
to look at, as any ip address that is exposed to the open internet should
have reverse lookups properly enabled. more and more mail hosts are
refusing to accept email these days from hosts whose reverse lookups are
fubar, as there is about a 95% positive correlation between bad reverse
lookups and spam.

if anyone is having this problem, you can send email to me through
welty@domain.elided, which forwards to rwelty@domain.elided

richard