Here is the latest update for the Gmail settings.
Please check PDF to view details.
Please notice and tell your customer.
Gmail only allow you to sent 500 email per day. If you have more than that, you must limit it first.
Otherwise, the Test Sent will Fail no matter what.
Also, if your Gmail register location is different than your DVR location, please make sure the security is not Lock.
The Gmail will lock down your location if your PC and DVR are not in the same city.