After you install SharePoint for your Exchange account, only the Administrator's account is added to the SharePoint site by default. You need to add users to the site using the SharePoint interface so that other users can log in.
To add users to the SharePoint site associated with your Exchange 2013 account:
1. Make sure that the SharePoint users are listed in the CONTROL PANEL on the Services > SharePoint page. If you need to create a SharePoint-only user (without an Exchange mailbox), click the Create Users button, fill in all the information, and make sure that all the "Services" boxes are not checked.
2. Log in to your SharePoint site as Administrator via CONTROL PANEL > Services > SharePoint, and click the link to access your SharePoint site. The Administrator is the user that was specified during SharePoint installation.
3. Navigate to Settings > Site Settings > Site Permissions.
4. Click Grant Permissions.
5. In the Grant Permissions window, you can either add users to a previously created group, or grant them permissions directly. To add users, you can type their email addresses into the Invite people to field.
6. Give permissions to the users you have added.
7. Choose whether to send the Welcome email to new users.
8. Click OK to create users.
To check permissions:
- Navigate to a site or a library where you need to check permissions.
- Go to Settings > Site Settings > Site Permissions and click Check permissions.
- Enter the email address of a user or select them from Global Address List.
- Click Check Now.
Now, added users can log in to the site using the credentials you specified in the CONTROL PANEL.