岁初天寒，新年伊始，新老客户，握手同欢。
In this cold winter, is about to begin the new year, new customers and old clients to celebrate together.
或者
感谢广大的客户和朋友一如既往的支持和信任，这是我们最宝贵的财富。值此新年佳节之际，XX公司全体同仁向您及您的家人致以最亲切的问候和最诚挚的祝福。
On the occasion of the New Year, may my wife and I extend to you and yours our warmest greetings, wishing you a happy New Year, your career greater success and your family happiness.
我们携手走过了不平凡的2009，让我们在2010再创佳绩!新的一年，XX公司将再接再历，继续帮助顾客取得更大的成功!
Good luck and great success in the coming New Year.
