I&#x27;ve had a few people self-host their own instances, and I like that this is possible.  As you say this is key-free, which with the benefit of hindsight was perhaps a mistake, but nowadays I&#x27;m happy enough with it.<p>Spammers would need to train their comments as ham for <i>every</i> domain - since if bayasian testing is done it is done on a per-site basis.  I think that&#x27;s probably the biggest reason why they&#x27;ve not bothered.