Hi, Dear xxx,
Are you interested in saving some money? Are you interesting in good quality with nice price? And are you interested in small order with fast delivery?（提问的方式投其所好）
So pls let you know we can offer all these for you, ABC Silicone is the TOP rtv liquid silicone factory in China more than 10 years. Below is our best seller, pls check it. Any interested, more information & FREE SAMPLE（免费样品投其所好）will be provided for your reference.
Hope to hear from you soon. Good Business Start Here!
Dear XX:
(Dear + 客户名称，不要用client, friend这种一看就是群发的词)
To thrill the market and develope the new products in the market, we are during our yearly biggest promotion. All of attached items enjouy discount up to 10% discount.
第一段: 说明促销目的和促销力度。有说服力的促销和折扣可以让促销活动事半功倍，反之，则会引起客户对促销活动和产品本身产生顾虑。
Our promotion will start from FEB. 10th. to FEB. 20th. Please catch up with this yearly biggest promotion to gain a big advantage in both price and market trends.
第二段：设定促销有效期，没有有效期的促销活动是没有灵魂的。给予客户以时间上的紧迫感才能让客户获得足够的采购动力。
Waiting for your active action.Best Regards.
最后一段为日常问候~