Dropbox space can be increased up to 16 GB for free!
Microsoft Onedrive: https://goo.gl/aHzqqG
Onedrive space can be increased up to 10 GB for free!
Google Drive: https://drive.google.com
The storage is shared across Google Drive, Gmail, and Google Photos.
Also try G Suite: https://goo.gl/74zz9T
G Suite is the best all round solution for any business/brand