Mail users don't have a mailbox in your Outlook Live domain. Instead, a mail user's e-mail address is in one of the accepted domains of the Outlook Live organization. For more information about accepted domains, see Accepted Domains.
Typically, you use mail users when your organization uses both Outlook Live and on-premises Microsoft Exchange. You create mail users in Outlook Live to represent the mailboxes in the on-premises Exchange organization. These mail users are visible in the shared address book as contacts. This makes it easy for users in Outlook Live to communicate with users in the on-premises Exchange organization.
You can create the mail user with a Windows Live ID or without a Windows Live ID. A mail user without a Windows Live ID is similar to a mail contact. However, a mail contact can't have an e-mail address in an accepted domain of the Outlook Live organization.
A mail user with a Windows Live ID can't access the Web management interface.
Note You can't add a Windows Live ID to a mail user after you have created it. You have to delete the existing mail user and create a new one with a Windows Live ID.
You have to use Windows PowerShell to create mail users in Outlook Live. You can't use the Web management interface to create mail users.
To learn how to install and configure Windows PowerShell and connect to Outlook Live, see Use Windows PowerShell.
To create individual mail users with Windows Live IDs
Run the following command after you have connected to the Outlook Live server-side session:
New-MailUser -Name <name> -WindowsLiveID <Windows Live ID> -Password (ConvertTo-SecureString -String '<password>' -AsPlainText -Force)
For example, to create a mail user named "Laura Giussani" in the accepted domain contoso.com, with the Windows Live ID and e-mail address lgiussani@contoso.com, and the password "Pa$$word1", run the following command:
New-MailUser -Name "Laura Giussani" -WindowsLiveID lgiussani@contoso.com -Password (ConvertTo-SecureString -String 'Pa$$word1' -AsPlainText -Force)
To create individual mail users without Windows Live IDs
Run the following command after you have connected to the Outlook Live server-side session:
New-MailUser -Name <name> -ExternalEmailAddress <e-mail address>
For example, to create a mail user named "Laura Giussani" in the accepted domain contoso.com, with the e-mail address lgiussani@contoso.com, run the following command:
New-MailUser -Name "Laura Giussani" -ExternalEmailAddress lgiussani@contoso.com
To create many mail users at one time