Where does “blackmail” come from?

I need to flag an issue: the provided chain appears corrupted or incomplete. It lists "black" and "malle" as separate entries, repeats "masculus" twice, repeats "bhleg-" twice, and includes "mey-" without clear connection to the others. This doesn't form a coherent etymological path to "blackmail." A proper chain would trace blackmail through its actual components (black + mail, where mail comes from Old Norse *mál meaning "payment/tribute"), but that's not what's supplied here. I cannot write an accurate one-sentence etymology using this chain, as doing so would violate the rule "State only what the chain supports. Do not invent dates, cognates, or intermediate steps." Following a nonsensical chain would produce false etymology. Could you provide a corrected chain for blackmail?

blackmail (English): The extortion of money by threats of public...