–New: free delivery by cart contents. Set a shipping class and a quantity — for example 4 items of "Effect fluids" — and from that quantity upwards the couriers’ prices go to zero.
–It works the same way a free-shipping coupon does, including on cash on delivery: the shop settles the freight with the courier, so the courier does not collect it at the door on a delivery the customer was told was free.
–Quantities count, not lines: four of the same product qualifies.
–The setting is in Sell & Ship → General → Discounts.