In some cases you want to create a user, but don't necessarily want this user to have an email account. Perhaps you want someone to look at the server to help out, or perhaps you want to use SharePoint as an extranet, and you want to allow a certain group of users to access SharePoint, but you don't want to host email for them. If you use the SBS Add User Wizard it forces you to create an email account right? Right?
In the SBS Add User Wizard, you can simply delete the email alias from
the User Account Information page and then complete the wizard.
Poof, a domain account that doesn't have an email address!