Once the SharePoint Online service administrator has set Manage External Users to Allow for a site collection in the SharePoint Online Administration Center, the site collection administrator can invite external users from outside the company and grant them appropriate permissions to access the site collection. Thus, the external users can access the company’s internal resources and collaborate with internal users.
nvite external users to a site collection
SharePoint site collections are created with Manage External Users set to Deny. You must ensure that the Manage External Users setting on the site collection is set to Allow before you can invite external users. If you try to invite an external user for a site collection with Manage External Users set to Deny, you will see an error message.
To invite external users to a site collection
1. On the site collection’s home page, click Site Actions in the upper-left corner of the page, and then click Site Settings from the drop-down menu.
2. Under Users and Permissions, click External user permissions. The Add External Users dialog box appears.
3. In the Users box, type the e-mail addresses for the external users you want to add.
4. In the Give Permission area, do one of the following:
* To assign users to a SharePoint group, click Add users to a SharePoint group, and then select a group from the list.
* To grant users individual permissions, click Grant users permission directly, and then select permission levels from the list.
5. To send an e-mail message to the new users, in the Send E-mail section, select the Send welcome e-mail check box. The message will include information about how to gain access to the SharePoint site. You can also include a personal message.
6. Click OK.
The invited user can now sign into your site collection by using the e-mail address you entered as their user name. If they do not have an existing Windows Live ID with this user name then they will need to create one before accessing the site.