There are a number of reasons why you may not be receiving email alerts for camera or NVR events, this article will explain what you should check to ensure your configuration is set up correctly.
Firstly, ensure the event is occurring on the camera (if applicable), you can do this by checking the camera event log:
Check NVR and camera events are being received by the NVR:
If camera events are not appearing in the NVR event log, ensure the correct rule is set up in the Event Rules:
Email alerts are done via the SMTP protocol, the SMTP details for the email server need to be configured on the NVR. If you are using Gmail as the SMTP server, you can see this article for more help
You configure the SMTP parameters in Network->Email
You should verify these details by sending a test email. If the test email fails, recheck the SMTP details.
Recipients of the email alerts also need to be configured, you can do that in the Recipient section:
Finally, configure an Event Rule to send an email alert based on an event:
You should then be able to receive email alerts from the NVR when an event occurs