Name

The Name section includes fields for the user’s first and last names, as well as the required Display Name and User Name fields. The most important entry is user name, which is the logon name for the Office 365 portal and email address for the user.

When assigning a user name, pay close attention to the domain name. If you have validated a custom domain, you can assign that domain to the user. Keep in mind that if you change the domain name for a user, his mailbox content does not change but he cannot log on with the previous user name. You’ll run into this problem only if you add a domain name to Office 365 after you have created users and then change the user names to the new domain. As soon as you do that, Lync Online and Outlook will not log the user on until you update the user’s domain in Lync 2010 and Outlook.