Have a Merry Christmas.
祝您圣诞愉快!
再给你增加两条：
May everything beautiful and best be condensed into this card. I sincerely
wish you happiness, cheerfulness and success.
愿一切最美好的祝福都能用这张贺卡表达，真诚地祝你幸福、快乐、成功！
Allow me to congratulate you on the arrival of Merry Christmas and to extend to you all my best wishes for your perfect health and lasting prosperity.
圣诞愉快，祝身体健康、事业发达。
I wish you good health and a happy life in the New Year!
Merry Christmas!Wish you happy and health!Good luck for you with the coming year!
Dear Mr/Ms,
Merry Christmas and have a good buiness in the new year.
Best Wishes,
your name
切记少提起工作上的合作，生意什么的，别人会认为你另有企图，虽然我们寄贺卡就为了生意。
仅仅是祝福就好。