It's joy to know you, wishing the nicest things always for you, not only today, but all the year through because you are really a joy to know.
认识你是一种快慰，愿你永远拥有最美好的东西，不仅今天拥有，而且天天拥有，因为认识你真是一种慰藉。
A friend is a loving companion at all times.
朋友是永久的知心伴侣。
Think of me sometimes while Alps and ocean divide us, but they ever will, unless you wish it. (Byron)
长相思，天涯海角；情不断，山水难隔。 --拜伦
You're wonderful friend, and I treasure you more with every year.
你是一位难得的挚友，我对你的珍重与岁俱增。
你好，Dear [Ex-boyfriend],
I hope this message finds you well. I just wanted to drop by and say hello, and to let you know that I still have fond memories of our time together. Although things didn't work out between us, I am grateful for the experiences we shared and the lessons I learned.
I hope you are doing well and that life is treating you kindly. If you ever need someone to talk to or just want to catch up, feel free to reach out.
Take care,
[Your Name]