To prevent a full storage the Collaboration Manager gives you the opinion to send a warning email. Please navigate to the Central Administration.
You have to set the ContentDatabase Creation to "Manually create databases." and fill in the prefixed names for the template and workspace databases.
Read more about ContentDatabase Creation here.
1. Choose the WebApplication(s)
2. Choose the value in percentage
3. Configurate the recipient, the subject and the body
4. Please confirm your settings with the "OK" button below.
5. Perfom an IISRESET /noforce