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When v3.1.0's sa-update looks for an update, it gets no TXT response (having an existing 0.1.3 record overrides the wildcard record), and therefore it sees no updates available. However, when v3.1.1 or above looks for an update, it gets "386156" returned.
The Backend
Details of the rule-update generation backend at updates.spamassassin.org can be read at SaUpdateBackend.
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