I think the key point in thier email is that it say......"You submitted a qualified entry......"
I think they are sending the email ONLY to those whose entries were NOT rejected outright initially for the random drawing.
As you know a heck of a lot entries are rejected outright, photo errors, obvious multiple entries, trying to trick with multiples by deliberate spellings and or b'day errors etc etc.....
So the number of emails would be way way less than 14.7 million !!
ALSO REMEMBER, you will get this email ONLY IF you gave a VALID (no spelling mistakes etc.) email address in your eDV form, and that address is still valid with your service provider.
Make sure you check junk/spam folders. If you have setup the email a/c to delete spam/junk as soon as they come, then you MAY not ever get this. Dbl chk those aspects.
Best !