Do you want to get negative messages in your Mail Box? Wait until you have only one PM in your mailbox. Then read the message, remove it, use your browser back button to return to the message, and remove it again. Voila -- your mailbox will now show that you have (-1) message.
I haven't tried it multiple times to get to higher negatives, but I assume it would.
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The cheaper the paper, the more important the information. Peter Lynch.
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Price is a crazy and incalculable thing, while Value is an intrinsic and indestructible thing. G.K. Chesterton