Fix BlueMail push notifications on Samsung Galaxy

One UI runs its own power management on top of Android’s, and each layer can hold mail back independently. If BlueMail only updates when you open it, work through all three settings below — fixing one and leaving the others usually changes nothing.

Set BlueMail to unrestricted

Settings → Apps → BlueMail → Battery → Unrestricted.

On older One UI versions this reads Battery → Battery optimisation → All apps → BlueMail → Don’t optimise.

Keep BlueMail out of Sleeping apps

Settings → Battery → Background usage limits (on some versions, Settings → Battery and device care → Battery → Background usage limits).

• Turn off Put unused apps to sleep — otherwise Samsung re-restricts BlueMail after a few days of not opening it, and the problem quietly comes back.
• Open Sleeping apps and Deep sleeping apps and remove BlueMail from both. Deep sleeping apps receive nothing at all until you launch them.

Turn off Adaptive battery

Settings → Battery → More battery settings → Adaptive battery.

Adaptive battery learns which apps you open and throttles the rest. A mail app you read rather than launch is exactly what it demotes.

If mail still arrives late

• Open Recents, long-press BlueMail’s icon and choose Keep open so the app is not swiped away by memory management.
• Check Settings → Notifications → App notifications → BlueMail is on, and that its mail channel is not set to silent.
• If Data Saver is on: Settings → Connections → Data usage → Data Saver → Allowed to use data while Data Saver is on → enable BlueMail.