Is it possible to find out what devices have been registered to receive iMessage with my Apple ID?
I can only see my phone number and Apple ID in iMessage settings, but not what devices are registered.
Itunes > Itunes Store > Click on email id after logging in (i.e. view account) > Manage Devices
That should get you a list of devices, that you have your appleid enabled on. You can check those device settings to see if iMessage is enabled and if yes, under what ID.