Dear (Друг),
I want to wish you happy birthday and hope you are doing well. It had been a long time since we met the last time, the distance plays its role unfortunately. But I want you to know that I always remembered this special day. You are a great friend, the one who I can rely on always. I really appreciate it. I want to wish you all the best: a lot of happiness, good luck in everything, success in your life in whatever you do.
May all your wishes come true. Happy birthday once more and enjoy your day. It is all yours
Miss you very much.
Your friend,
Имя