I'd say don't send overnight. That's very spendy. I was always looking at the exchange date of the 4th as the day to get it in the mail. I'm sure your partner will understand.
I will send the address to you! 
Mine wont be in the mail till Monday or Tuesday. I depend on my mom to do that stuff for me now.... 
So for Everyone: Don't worry if your packages are a couple days later. If its over a week let me know and I'll check with your partner to make sure they remember! 
Let me know if anyone has any other questions!
-chelsey