If you are noticing slow performance or other issues, it’s much likely that the database has grown beyond its regular capacity. Because everything gets stored in identity folders. And this problem gets even worse if you are the kind of the user who gets large files as attachments. Outlook client can get very slow and might even start functioning incorrectly due to the oversizing of the identity folders. Outlook for Mac, from Microsoft, has the same problem. More emails you get, the largest your database gets. This is due to the increase in the size of ‘identity’ or ‘profile’ folders database. Emails are so common and rich of data these days that it’s very common for any email client to quickly become sluggish and slow.