Μετάφραση - Αγγλικά-Κινέζικα απλοποιημένα - what's up? i just saw you e-mail. i finally...

I think that "what's up" is more like a "hello". If so, you should change it into "你好号码？", otherwise in Chinese it sound's like something bad happened and you are asking what happened, or that you had been a little disturbed by that mail.