I am trying to start my server remotely with this:
ssh email@example.com /sbin/reboot
And keep getting this back
ssh: connect to host xxx.xx.xx.xx port 22: Operation timed out
Why can't I start my server?
Reboot is for restarting your machine, not for starting if it is currently powered down. If you want that, you need a 'wake on lan' tool.
In order to connect to a host using SSH, you need the SSH service to be running in the target machine. That's the reason for the timeout.
What you need is to setup the server for Wake-on-LAN. That means that when the LAN adapter gets a certain signal, it will start the physical machine. For this, you usually have to follow certain steps:
Depending on the OS you're trying to connect to, you can Google a tutorial for setting up Wake on Lan (WoL) on your flavor of OS.
You can power it on by logging on the server's IMM, iLO, or something similar and look for the Power option. If you don't have access to that, then someone at the site needs to press the power button.