Some organizations, such as the MAPS RBL and MAPS DUL, publish lists that identify potential sources of spam and email abuse. The blq utility is a Perl script that queries one or more of these lists to determine if a particular host is listed.
It works something like this ...
$ <strong>blq rbl,dul 127.0.0.2</strong>
127.0.0.2 : blackholes.mail-abuse.org : BLOCKED
127.0.0.2 : dialups.mail-abuse.org : ok
Version 1.23 (13-Nov-2002) - Added new tags: dsbl, dsbl-list, dsbl-multihop, dsbl-unconfirmed.
Version 1.22 (10-Nov-2002) - Adds -n option to suppress hostname lookups and display numeric addresses. Now gives error if DNS lookup for TXT record fails.
Version 1.21 (09-Nov-2002) - Added rfci tag.
Version 1.20 (03-Nov-2002) - Adds -t option to retrieve TXT records. Added several new tags: pdl, ordb, njabl, xbl, fiveten, spamcop, hil. Dropped deprecated orbs entries. Changed default from rbl to an aggregate of sbl, rsl, pdl, opm, Osirusoft relays.
Version 1.19 (29-Apr-2002) - Changed startup options from -W to -w, for compatibility with older perl versions.
Version 1.18 (24-Apr-2002) - Minor internal cleanups.
Version 1.17 (24-Feb-2002) - Adds several new tags (opm, opm-wingate, opm-socks, opm-http, and opm-all) to query the Open Proxy Monitor List. The rrss and orbs tags are now officially deprecated and have been removed from the man page. Perl warnings (-W) are now enabled.
Version 1.16 - Not released to the public.
Version 1.15 (23-Feb-2002) - An rsl tag to query the Relay Stop List.
Version 1.14 (30-Jan-2002) - Omits blocktest from the osirusoft aggregate, since it should not be used to filter email. It still appears in the all aggregate, though.
Version 1.13 (30-Jan-2002) - Adds an sbl tag to query the Spamhaus Block List. The spamhaus tag removed from the osirusoft aggregate query; it's an alternate feed of SBL.
Version 1.12 (08-Oct-2001) - Depreciates (now defunct) ORBS and adds the set of osirusoft.com zones. It also adds an -a option to display the specified value of a site is listed.
Version 1.11 (10-May-2001) - Adds all-orbs to query the complete set of ORBS servers.
Version 1.10 (10-May-2001) - Corrects the ORBS server to inputs.orbs.org.
Version 1.9 (07-May-2000) - Minor update. Internal code cleanups. Adds one change that may speed up response to server failures if you have a long resolver searchlist.
Version 1.8 (05-May-2000) - Major update. Adds support to query multiple lists, or even saying "blq all ..." The set of built-in lists has been updated and expanded.