Right after installing DNP you should setup DNP system settings. They need to be correctly setup to send e-mail messages and work with backup/restore module.
In order to access System Settings page login under "serveradmin" and navigate to "Configuration -> System Settings" page.
SMTP Server Settings
Specify correct SMTP server settings to allow DNP send e-mail messages. Please, keep in mind that the application that sends e-mail messages is DNP Enterprise Server, not Portal.
Server - IP or hostname of mail server. If you want to send messages through SmarterMail then make sure it is an IP that bound to SmarterMail mail domain.
Port - SMTP port to use. By default it is 25.
User and Password - if you have SMTP relays disabled on mail server you should specify username and password of the account that has rights to send e-mail messages.
Enable SSL - if your SMTP is configured to accept only SSL client connections, tick this checkbox.
Backup Folder Path - physical path to the folder where temporary backup files will be placed. Make sure the account of Enterprise Server application pool has write access to this folder. The pool of DNP Enterprise Server that has been upgraded from 1.5.3 to 2.x works under "NETWORK SERVICE" account, pool of clean DNP Enterprise Server 2.x works under "DNPEnterpriseServer" account, so those accounts should have "write" NTFS access to backups temporary folder.