My notifications are delayed and my mail isn't syncing quickly, or until I open Outlook for Android. Battery Optimization Settings

We recommend that you check your power saving Android system settings. If settings are strict, Outlook is not granted access to connect to the network in the background and we cannot fetch your notifications or messages until you open the app.

Go to your system Settings, then Device Maintenance, then Battery Settings.

Turn off battery optimization for Outlook to increase performance speeds.