Dear Professor.XX,
May happiness follow you everywhere …just like we do.
愿快乐随时与您同在——如同我们与您寸步不离.
Best wishes for you and your family.
祝福您及您的家人.
Noel!(或Merry Christmas!)
圣诞快乐!
Yours sincerely
XXX
it's okay,不知道你忧虑啥呢~