Hi XXX,
Today/Tomorrow/xxxth is your xxxth birthday. At this moment, I would like to wish you a happy birthday. Receive heaps of gifts and have fun with you family and friends! I also wish you to have a wonderful year, being healther and fulfilled with love and happiness, also being more successful with your work! Although I cannot be with you on this/that day, you are always on my mind, and I'd like to send all my warmest blessings through the Internet.
Happy Birthday!
Best wishes,
XXX