on this documentation page: https://cwiki.apache.org/confluence/display/SPAMASSASSIN/UpgradingVersion
"If you install using a Linux package installer: Debian unstable: apt-get install spamassassin " what is the meaning of "unstable" ? it sounds scary, like the package should not be run in live mail systems, but then why would it be in the package mgr and not in a development package version?
