How can I politely ask for someone's address?
I'm sending out Christmas/holiday cards to some Japanese friends this year. However, I can't seem to find someone's address. I feel bad about asking again for their address.

!) How can I let her know that I've misplaced her address, and was wondering if I could get it again? I'm afraid of sounding too rude. Is there a polite way to ask for her address again, and ask if it's okay that I send her a card?

2) If I had an address but am not sure if it's still correct, is there a way to ask if that address is still correct?
Thank you. ^_^

Question

How can I politely ask for someone's address?
I'm sending out Christmas/holiday cards to some Japanese friends this year. However, I can't seem to find someone's address. I feel bad about asking again for their address.

!) How can I let her know that I've misplaced her address, and was wondering if I could get it again? I'm afraid of sounding too rude. Is there a polite way to ask for her address again, and ask if it's okay that I send her a card?

2) If I had an address but am not sure if it's still correct, is there a way to ask if that address is still correct? 
Thank you. ^_^

Answer

You can say that you would like them to email it to you so you can copy and paste because your writing isn't literate! (probably its not true, but...)

You can say:

(if you're friends)
ごめんだけど、住所をもう一回教えてもらっていいかな？
年賀状を送りたいんだけど、住所を間違えちゃったみたい！

If you want to be super polite:
申し訳ありませんが、住所を私が間違って記録したみたいです。
もう一度教えていただけませんか？
ありがとうございます。