Email storage isn't lowering after deleting all emails?

Email storage isn't lowering after deleting all emails?

Hi,

I backed up one of my users emails, and then deleted all but the most recent 100 emails.
I also emptied all the other folders including the trash folder.

However, when i login on my admin account and go into control panel, it is still saying that this user is using 46% of his storage.

Can anyone help me why this storage isnt changing?

Cheers!

Richard