Depending on your school, you should utilize dedicated mobile email app to add email account. This is to ensure best experience and to avoid any issues.
- If you are are Google School, please see the guide below on how to add an account to Gmail app: Add another email account to the Gmail app - Android - Gmail Help
- If you are Microsoft School, please see the guide below on how to add an account to Outlook app: Setup Outlook for iOS and Android - Microsoft Support