Need advice with brand name protect

Hello,

We have two year old shop with our brand name, with 10 brand domains (.COM included). Brand name is not registrated as a trade mark.

Today we got email from china hosting company like this:

Dear CEO or General Manager,

Please read this letter carefully since this is an urgent case. We are an agency engaging in registering brand name and domain names. Today, our center received an application from (business name) International Ltd…

Need advice with brand name protect