Not long ago, Google Apps and Gmail users have to rely on third party tools to download their data. Finally, now you can backup everything locally!
1. Go to your Google Account Page – https://www.google.com/settings/personalinfo
2. Select Data Tools – https://www.google.com/settings/datatools
3. Download Data – https://www.google.com/settings/takeout
4. Check the Apps that you wish to archive and click “Create Archive”
The beauty of this tool is it backup your Apps settings too!
Btw, please note that although it is called Archive, it is not a real time archiving. It is more like a backup tool.