Microsoft has introduced a new method of securely sharing files and folders stored in SharePoint Online and OneDrive with external users. These are welcome changes, because frankly, the previous method was a little clunky and was not always reliable. Formerly, when sharing a file with a user external to your corporation active directory, this user was sent an invitation and was required to log in using a Microsoft Account or Work or School Account. They were then added to your active directory as a guest and given permission to the file.
Now has made the process of sharing files with external recipients much easier. Microsoft is also confident that the external user will be granted access 100% of the time. The initial procedure for sharing files and folders remain the same. Now, when a user shares a document or file with an external user by creating a shareable link, the recipient will receive a one-time, time limited, code that they can use to verify their identity. They are no longer required to log in using a Microsoft Account or Work or School Account.
SharePoint Administrators can control how often external users must validate their email address. This is controlled from the SharePoint Admin Center in the Sharing area.
As a bonus that shows OneDrive for Business increasing popularity, Microsoft is updating the storage allocation from 1 TB plus .5 GB per user license purchased to 1 TB plus 10 GB per user license purchased. Once Microsoft has completed the rollout of this change, Administrators will see the increased storage reflected in their SharePoint Online admin center.