Interesting. Won't it just wait until the wallet comes back online. In the case of someone sending to a valid address not yet created would it not suddenly gain that amount when it was created?

I thought it's a bit like a text message. Waits till it turns on then sends it.

If not people need to leave their wallets on all the time and we know that isn't true. So maybe if there was a time limit of X days/weeks/months?