v2.3 - 2005-06-09
- FEATURE: Report to subject line (for clients with limited filter
  capabilities)
v2.2 - 2005-02-02
- FEATURE: New set of X-RBLcheck headers, optimized for bayesian filtering (as
  used in Thunderbird).
- FEATURE: Profiles, selectable from a command line parameter.
- FIXED: Some DNS servers return an IP address of a 'page not found' website
  if the name cannot be resolved. RBLcheck now checks whether the resulting
  IP address is in the 127.x.x.x range.
v2.1 - 2005-01-03
- CHANGED: Header parsing has improved, it now first tries to find an IP
  address according to the RFC, if not found it will grab the last string that
  looks like an IP address. The keyword ReceivedRFC has been dropped because of
  this.
- FEATURE: New keyword HitIP, which is the opposite of SkipIP. If the trigger
  is reached by use of HitIP, and HaltAtTrigger is set to 1, no DNS lookups
  will occur. (Fast!)
v2.0 - 2004-11-07
- FEATURE: Parallel DNS requests; major performance gain!
- FEATURE: Adjustable DNS lookup timeout
- FEATURE: Each handled email gets a unique id, which is used on every log
  line. This helps identifying log entries when 2 or more instances of RBLcheck
  run at the same time.
- FEATURE: Follows RFC to find IP-address in header line or (configurable)
  use anything that looks like an IP-address anywhere within header line.
- FEATURE: Return code (error level) can be configured to reflect the result.
- CHANGED: Default for TriggerLevel is now 10. All score values in the shipped
  RBLcheck.ini are now integers (in fact they are multiplied by 10).
v1.5 - 2004-07-27
- FIXED: Files are closed as soon as possible to prevent file locking.
- FIXED: Large messages were handled very slow.
v1.4 - 2004-04-23
- FIXED: Tabs are now allowed in ini file
- FEATURE: Use RxSock.dll instead of host.exe, better error handling of
  lookup conditions
- FEATURE: Logging to screen, independent of logging to logfile
- FEATURE: Version number of RBLcheck can be added in header
- FEATURE: Sample ini file has new/changed RBL's, as used by author
  (multihop.dsbl and unconfirmed.dsbl removed, because dsbl is quite slow)
v1.3 - 2004-03-21
- FEATURE: Stop checking as soon as triggerlevel is reached
- FEATURE: Last hops of message can be skipped
v1.2 - 2004-02-01
- FIXED: If hit(s) found but final score is 0, it creates the header
  X-RBLcheck: negative
v1.1 - 2004-01-24
- FIXED: Better error handling
- FIXED: Check each IP address only once, even if found in more Received
  headers
- FIXED: Only 1st line of folded header line was interpreted
- FIXED: Now only the from field of the Received header is being searched
  for an IP address
- FIXED: Don't check private, reserved or loopback IP address ranges
- FEATURE: Levels of logging, including no logging
- FEATURE: Configurable IP addresses to not test (SMTP servers of
  provider)
v1.0 - 2004-01-11
- First public version