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Bollocks. The owner of the email address is by definition authorized to enter. If you build a house on my land the house does not belong to you.
It won't boot until you press a key to continue. Many Linux machines don't have any facility for that, either because they are a tablet with no physical keyboard or because they are a headless server with no-one around to operate them locally.
I can see there will be a market for a USB device that emulates a keyboard and sends a keypress at a predetermined delay after power on. It shouldn't cost much to make and can be easily installed in servers that are required to reboot after a power outage.