mailcow-dockerized/data/conf/rspamd/local.d/statistic.conf

classifier "bayes" {
    tokenizer {
    name = "osb";
    }

    backend = "redis";
    servers = "redis:6379";
    min_tokens = 11;
    min_learns = 200;
    autolearn = true;

    per_user = <<EOD
return function(task)
    local rcpt = task:get_recipients(1)

if rcpt then
    one_rcpt = rcpt[1]
    if one_rcpt['domain'] then
        return one_rcpt['domain']
    end
end

return nil
end
EOD

    statfile {
        symbol = "BAYES_HAM";
        spam = false;
    }
    statfile {
        symbol = "BAYES_SPAM";
        spam = true;
    }
    learn_condition =<<EOD
return function(task, is_spam, is_unlearn)
    local prob = task:get_mempool():get_variable('bayes_prob', 'double')

    if prob then
        local in_class = false
        local cl
        if is_spam then
            cl = 'spam'
            in_class = prob >= 0.95
        else
            cl = 'ham'
            in_class = prob <= 0.05
        end

        if in_class then
            return false,string.format('already in class %s; probability %.2f%%',
            cl, math.abs((prob - 0.5) * 200.0))
        end
    end

    return true
end
EOD
}