What the engine does not send verifiedimportant
Nine of the thirty-three counters exist only in the browser, with their arithmetic written in the console's own source.
In detail
The list and its formulas, because a monitoring page has to reproduce them exactly: active = connections − connecting − idle; failures = the eleven error counters listed in its own entry; allgreylisted = greylisted + forcedgreylisted + untriedgreylisted; allerrors = unassignable + errors + noips + notsecure + nobody + forcederrors + untriederrors; success = deliveries ÷ (deliveries + failures); errorRate = failures ÷ (deliveries + failures); totalSuccess and totalErrors = this slice's deliveries or failures ÷ the same totals across every slice; queued = queue + assigned + parked. Two of those — failures and allerrors — are the reason this chapter has a discrepancy section. We reproduce the formulas we agree with and correct the two we do not, rather than inventing our own vocabulary: an operator comparing our page with the console has to be able to see the same numbers.