Release Goals
There are no currently defined release goals for new versions beyond continued bug fixes and enhancements as discussed on the development list and through bugzilla.
Release Schedule
The Apache SpamAssassin project goal is to produce three major or minor release per year with release candidates proposed on or closely to January 30th, April 30th & September 30th of each year.
Release Support
A major release is supported for no less than 6 months after the release of the next major release.
This means that as of November 30, 2014, all versions prior to 3.4.0 are considered unsupported.