How the email is configured

Hi Team,

These days, I frequently got the below email.

"You are receiving this e-mail message because you are an administrator of the following SharePoint Web site, which has exceeded the warning level for storage: https://mysite.com/personal/sanny/. To see how much storage is being taken up by this site, go to the View site collection usage summary: https://mysite.com/personal/sanny/_layouts/Usage.aspx."

I don't have any documents in my personal site. Could you please tell me where this configuration was done?

Thanks in Advance

Krishnasandeep