Anyone who'd report an e-mail as "abusive" for lowballing is a d'bag themselves. Don't like the offer? Don't respond or counter with a higher one. Don't take it personally -- negotiation is just business even if the starting points are miles apart.

As a New Yorker (who's dealt in business with quite a few Greeks, Armenians, Russians, Persians, Turks, and Jewish people of various nationalities -- all of which have haggling strongly culturally ingrained), I'm USED to hardass haggling and NEVER get insulted. If you lose your cool and take it personal, the other party wins by default.

Example: my initial offer for my condo was about 20% below ask, which would insult a lot of sellers in other parts of the US -- we met roughly in the middle at the end, as expected.