Trash: OS X maintains different Trash bins for different apps and storage devices. CleanMyMac deletes unwanted iTunes extras and lets you choose old backups and iOS software updates for removal, helping you reclaim space on your Mac. Over time, the app accumulates junk on your Mac in the form of old iOS device and app backups, old software updates, broken downloads and more. It helps you keep iOS backups, install iOS software updates and download media from the iTunes Store.

ITunes Junk: iTunes is lot more than a typical music management app. CleanMyMac automatically does that for you. Sure, you can manually clean them out individually, but it would take hours to browse through your mailbox searching for attachments and deleting them.

But once they are downloaded (using the Mail app), they get saved on your Mac and remain there occupying precious disk space.

Mail Attachments: Attachments in emails are often downloaded for one time use.