If your domain predates the trademark, and you're using the domain and not squatting on an empty page then I don't see why you would be obligated to give it up.

If your domain predates the trademark, and you're using the domain and not squatting on an empty page then I don't see why you would be obligated to give it up. If they just sent a strongly worded letter/email I'd be tempted to just ignore it really. I am however not a lawyer and you might want to consult one. You might be interested in reading about Nissan.com, where the owner has had an ongoing struggling with the Nissan Motor Company over the domain name.