You can change notification sounds for emails and calendar events directly within the new Outlook app for Windows. In classic Outlook, you can choose whether to play a sound when a new email arrives.

The settings will automatically save, and the next time you delete an email, it will not show up the message. Make sure to test it out. Read: Email notification sound is not working. Cache is one of ...

You can change your Outlook theme in your account settings while logged in through a browser or in the Mac and Windows apps.