求助：收到老外威胁信，该如何是好？

[Dr.Xue]

昨天一位加拿大买家来信想要我的域名，我回信用卡180K，没想到老外今天总算回信了，还说请教了律师了，老外信的内容如下：
Dear Xue,
We register HoXXX has a trademark, $180.000 is completely rudiculous! If you have some knowledge regarding domain name property, you know the process.
We can offer you $2000.00 to close this deal. Otherwise we will go to court and you won't get anything.
We will both lose money and time.
I already inform my lawyer.

Waiting for your answer.

Cam

请教各位大佬，我该如何回啊，其实这个域名我查了一下，是一个单词的过去式。

晕倒，碰到这种事，今年运气不怎么样啊。

[哈啦]

你確定這是一個常用單字嗎？你有拿這個域名做任何和那家公司(產品)有關的網站嗎？如果沒有，就不用怕它。
你回說，This is a common English word and having a trademark does not mean you own this word, or you just try to reverse hijack any domain names you want?
Here is wiki link :
http://en.wikipedia.org/wiki/Reverse_domain_hijacking

中文意思是說，這是一個普通的英文字，有註冊商標不表示你就擁有這個英文單字，還是你只是想搞個域名反劫持？

你甚至可以說，我早已在我的國家註冊了這個trademark。I also had this word trademaked in my country already.