The South Korean Network Blocking List
Beginning in late 2001, we started receiving vast amounts of junk e-mail
(better known as spam) from Korean networks.
Some of it was in Korean, a language that nobody here understands, some
was in English.
Despite repeated attempts to contact system managers to alert them to the
problem, we never received even a single acknowledgement to any of
So, with regret, we have blocked mail from most South Korean networks.
The blocking mechanism is a DNSBL (DNS blocking list) called
It lists the numeric addresses of Korean networks, in a form that mail
systems can check efficiently.
See http://www.dnsbl.com/ for more
info on DNSBLs.
DNSBLs are designed for software like sendmail, qmail, and postfix that
handle mail transfers from one system to another.
You can't easily use them from user programs like Eudora or Outlook.
If you're not sure whether your mail system can use a DNSBL, it probably
Consult the people who run your mail system and see if they want to use it.
Who can use korea.services.net ?
As far as I'm concerned, anyone is allowed to use it.
Please be sure that your mail software is set up to use a local DNS server
(BIND is the most common) rather than querying us directly, to limit the
If the load becomes too large, we may ask heavy users to host mirror copies
of the data.
(If you don't understand these instructions, please consult the people
who run your mail system, or the vendor that sold you your mail software.)
What exactly is in the database?
The database lists most IP address ranges assigned to Korea by APNIC,
plus any older ARIN ranges with a history of sending spam.
The list includes networks, not individual computers.
As networks clean up their act, get rid of their spammers, fix their
abusable relays and proxies, and set up a reasonable procedure to receive
and act on complaints, I have started removing well run networks from the list.
My goal is to stop the flow of spam, not to cut anyone (other than spammers)
off from the Net.
Note: The database includes networks, not individual computers. Do
not write to ask to have your computer removed, unless your entire network
has its spam problem under control.
Is an address in the list ?
For information about an address' entry in the list at
korea.services.net, enter it as an IP address, four numbers
separated by dots, and click Lookup.
Attention Postfix Users:
Did you come here because korea.services.net appears to be blocking large
amounts of non-Korean mail?
Some widely distributed instructions for setting up DNSBLs in Postfix
can be misleading.
Be sure that this DNSBL is listed in a reject_rbl_client line
in your configuration file.
Do not use a reject_rhsbl_client line.
If you do Postfix will look up domain names, which it shouldn't,
rather than IP addresses, which is what it should do.
$Date: 2006/09/04 21:26:52 $ 220.127.116.11