External users can't find users in the people picker in SharePoint Online
An external user tries to share a SharePoint Online resource with an Office 365 user. But, when they type either the user's name or partial email address, the people picker doesn’t return results.
To work around this issue, external users must type the complete email address of an internal user to share anything within SharePoint Online with those users.
This issue occurs because external users aren't able to run Active Directory queries within the people picker in SharePoint Online.
Id. de artículo: 3194901 - Última revisión: 09/26/2016 18:56:00 - Revisión: 1.0
Microsoft SharePoint Online