Suppose you want to receive automatic email notifications only when users remove files from a library on a SharePoint site How do you do this?

In a Sharepoint, one can register for alerts on the entire library.

1. Browse to the library.
2. Click Actions > Alert Me.
3. Choose 'change type' as 'Items are deleted'.
4. Keep the other sections with default values. Click OK.

This will allow you t receive alerts upon file deletion form the Sharepoint library. If you wish to retain files and create a hold on them, the best way to manage is using a Records Centre site.