SpamAssassin version 3.3.1 has not had a rule update since 2016-10-14. 20161014: Spam and ham are above threshold of 150,000: http://ruleqa.spamassassin.org/?daterev=20161014 20161014: Spam: 209998, Ham: 193211
The spam and ham counts on which this script alerts are from http://ruleqa.spamassassin.org/?daterev=20161014 Click "(source details)" (it's tiny and low contrast). It's from the second and third columns of the line that ends with "(all messages)" The source to this script is http://www.chaosreigns.com/sa/update-version-mon.pl It looks like both the weekly and nightly masschecks need to have sufficient corpora in order for an update to be generated.
