You can free up space on your Mac by manually deleting files, cleaning out your Downloads folder, emptying your trash, and more.
You can swipe to delete messages in the iPhone's Mail app, but you'll need to enable this option in Settings.
But if you use Google Drive, all your photos, videos and other random documents might be eating up the 15GB of free storage Google Drive provides. If you run out of storage, you'll see a message ...