Big Mail can send you notifications when you receive new messages.
By default Big Mail notifications are off. To enable them go to Settings and Preferences > General > Notifications. You can choose to receive notifications for:
On macOS you’ll receive notifications near real time. Due to power constraints on iOS, and the fact Big Mail doesn’t use third party servers, notifications are polled for every 5 to 10 minutes. Factors such as low battery or low power mode will decrease the frequency at which Big Mail can check for notifications.
As a general rule of thumb, the more you use Big Mail on iOS, the more frequently it will check for notifications and refresh in the background.
If you require realtime notifications, you’ll need to use a ‘push’ email service provider.