According to Neowin, Microsoft is testing a new feature where you can save your Outlook email attachments directly to your OneDrive account. The new feature is only available to some users and has not been rolled out to all Outlook users as of yet, but hopefully the new feature will be released system-wide soon.
I think it would definitely be quite handy to view an email on my Windows Phone, save the email attachment to OneDrive, and then pick up my Windows 8.1 tablet to view the email attachment later. It seems Microsoft is starting to test new ways of creating a universal Windows experience. At this time, you can only view the email attachment or download it to your PC or tablet.
This new added Outlook feature will definitely be more convenient for users by saving attachments to OneDrive and then being able to use on another device (that has the OneDrive app installed). This new feature will certainly add a new level of versatility to Windows and its OneDrive cloud storage system.
Let us know if your Outlook account has access to this new feature and if you like it in the comments section.