box and google are 2 cloud vendors but you can log in using your google account
then go to //app.box.com/services/browse/official
and look for the gmail apphttps://app.box.com/services/browse/my/gmail
Box is integrated with Gmail to make emailing attachments easier than it has ever been. Avoid having to download and attach files by sending them to Gmail directly from your Box account.
To use Gmail, right click on a file or folder and select “Send with Gmail” if you are using a normal Gmail account or “Send with Google Apps Mail” if you are using Gmail through your own domain. Input your username and password, and you will be taken to Gmail’s compose email screen. There will already be a link to the file, and you can create the rest of your email as normal.
Web App Integrations
Send with Gmail: Send Box.net content to Gmail
Send with Google Apps Mail: Send Box.net content to Gmail for your domain