2019-02-28: 1.4.4 - added the --append option
2018-05-30: 1.4.3 - removing spamcannibal.org from the documentation and default configuration
2018-05-25: 1.4.2 - removing dnsbl.cyberlogic.net from the documentation and default configuration
2017-07-17: 1.4.1 - Perl 5.26 support
2017-04-18: 1.4.0 - IPv6 support
2016-06-07: 1.3.8 - allowing Nagios::Plugins for older distributions
2015-02-01: 1.3.7 - now depends on Monitoring::Plugins (Nagios::Plugins
                    is deprecated)
2014-12-05: 1.3.6 - removed dependency on Data::Dumper
2014-09-21: 1.3.5 - fixed the default critical and warning range
2014-09-20: 1.3.4 - parameter validation fix
2014-08-09: 1.3.3 - parameter validation
2014-01-30: 1.3.2 - documentation and dependecies update
2013-09-26: 1.3.1 - disabled embedded Perl
2011-07-11: 1.3.0 - whitelistings support
2011-03-22: 1.2.2 - bug fix release (dependencies fixed)
2010-07-05: 1.2.1 - bug fix release (see Changes)
2010-04-08: 1.2.0 - improved parallel checks and several fixes
2009-10-27: 1.1.0 - parallel checks
2009-     : 1.0.2 - --retry command line argument to specify DNS retries
2009-01-06: 1.0.1 - Execution time in the performance data
2008-12-29: 1.0.0 - Initial release