If you currently use the SBL by querying the master zone sbl.spamhaus.org then you can ignore this message.
If you are using the SBL via 3rd party composite DNSBLs and not directly from sbl.spamhaus.org, then please read this as the following change affects your DNSBL setup.
For a long time the SBL has been available either directly from Spamhaus (as sbl.spamhaus.org) or via 3rd party composite zones such as relays.osirusoft.com (as spamhaus.relays.osirusoft.com) and blackholes.easynet.nl which import SBL data from Spamhaus. This distribution is now changing. In order to better manage SBL logistics, DNSBL zone and query traffic, from Monday 11 August 2003 the SBL should only be available from sbl.spamhaus.org.
The fact the SBL was available from multiple DNSBLs was causing some confusion, plus other small factors (such as the different zones having different build times - which for example meant that we'd tell someone an IP had been removed, but they'd contact us a few hours later to say it was still blocked), plus the likely emergence of further composite lists which may add confusion, meant that it was time to make a change now rather than in a year or two.