The Default Notification Collection is an Identity Vault object that contains a set of e-mail notification templates and an SMTP server that is used when sending e-mails generated from the templates.
The predefined e-mail notification templates are included in the Default Notification Collection. Any custom templates that you create are also added to the collection. You must define the SMTP server that you want associated with the collection. For more information, see Section 2.0, Designating an E-Mail Server.