How do I change the alert sounds in Outlook for Mac?

casagordita 

This is how to change the alert sounds when using "New Outlook" for Mac:

1. First, you will need a sound set to install. Here is one on GitHub from the old https://en.wikipedia.org/wiki/Microsoft_Entourage days:
   https://github.com/l337-haxx0r/microsoft-soundset
2. Unzip the File. It will look like a folder ending in .eragesoundset — keep this folder intact and do not change the file extension or edit any of the files inside of this folder!
3. Next, you will need to locate the Sound Sets folder. It is located at:
   ~/Library/Group Containers/UBF8T346G9.Office/Outlook/Outlook Sound Sets
4. Drag the 'Microsoft Sound Set.eragesoundset' folder into the "Outlook Sound Sets folder"
5. Now, switch to Outlook and go to the Help menu in the menu bar and click on it.
6. Select 'Revert to Legacy Outlook' from Outlook's Help menu — you will get a short survey as to why you are reverting to Legacy Outlook, if you want to tell them it's because you're trying to change the sound set… this is your chance to tell Microsoft.
7. Open up Legacy Outlook's preferences from the Outlook menu in the menu bar.
8. Click on "Notifications and Sounds".
9. Click on the "Sound set" pulldown menu, and you should now be able to choose the "Microsoft Sound Set" as an option. 
10. Finally, from the Outlook menu inside of the menu bar, select 'New Outlook' — the sound set you selected in step 9 will now be your soundset inside of New Outlook. I hope that helps!