External users cannot be an administrator for a site collection.External users do not add quota to the overall tenant storage pool (this is determined by licensed users only).They also cannot edit their own profile, change their photo, or see aggregated tasks. External users cannot see the company-wide newsfeed.

This means that they do not have their own SkyDrive Pro document library. External users cannot create their own personal sites (what used to be referred to as My Sites).From the documentation, the following paragraph describes what external users are not allowed to do: If you don’t know what an external user is, or what differences exist between external and normal fully licensed users, the official documentation can be found here on the Office365 site. In Office365/SharePoint Online, you can use the External Sharing feature to invite external users to access your SharePoint Online sites and collaborate. With just a flip of a few administrative levers however, you can enable profiles for your external users. According to official documentation from Microsoft, external users in Office365 tenants are not supposed to be able to edit their own profiles (and pictures).

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