I'm also an advocate of receiving the email sooner. Why not send it shortly after midnight in the users timezone so it sits in the users inbox when he wakes up.
At 9AM I'm already at work, had 2 cups of coffee, finished my morning tech news and started getting in the zone.
Ideally the user would choose the time the mail gets delivered. I have to have my phone on during the night in case of emergency and there is nothing more infuriating to me than a company that sends me email in the middle of the night, causing my phone to beep and wake me up.
Take control of your phone: use an app like Tasker to set up profiles to silence notifications except for ones you specify, like phone calls and messages from certain numbers.
As another Spanish based worker, a little earlier would be better - at 7, say, something to read over breakfast. But that's a very minor complaint!