Android 6 and 7 (Marshmallow and Nougat) have some new tools built into the OS which can affect the performance of applications such as BlueMail.
One of them is the “Doze” tool that turns off your device’s Network connection if the device hasn’t been touched or moved for a period of time. This can lead to a delay in receiving Notifications for emails you were waiting for.
In order to allow for Instant Notifications on BlueMail, we highly suggest you “Exclude” BlueMail from this list.
To do so: If you have received a message on BlueMail regarding this, simply click the “Yes” button and you will be prompted to easily add BlueMail to the “Don’t Optimize” list.
If not, Open your Device’s Settings menu | tap Battery | tap the “More” button on the action bar at the top right | select Battery optimization.
On the Battery optimization screen, switch to the All apps list from the drop-down menu to view all of the apps on your device.
Tap BlueMail from the menu and select Don’t optimize.
Enjoy your Instant Notifications!