You've likely configured the device correctly.
Since the Email Notification is outbound, the SMTP server of the ISP you're with typically needs to be configured as the outbound SMTP server as most ISP block open relay. My ISP doesn't require authentication to their SMTP server when I'm on their network - i.e. using an IP Address from their network. When I'm outside their network, I require authentication.
In short, if you can send email from one of your internal mail clients (Outlook, Eudora, etc.), configuring your router with the same settings should yield the same results. In short, possible scenarios:
Scenario 1:
FROM: DIR857@myisp.com
TO: myemailaddy@myisp.com
SMTP: smtp.myisp.com
PORT: 25
Authentication: Unchecked
Scenario 2:
FROM: DIR857@myisp.com
TO: myemailaddy@myisp.com
SMTP: smtp.myisp.com
PORT: 25
Authentication: Checked
SMTP Authentication: username
SMTP Password: usernamepassword
Reboot the router, you should receive an email from the DIR-857. Scheduled email or email now will produce no result as it is being sent to the FROM email address as indicated in the log.
Note that the FROM address doesn't actually have to be a "real" email address but you can configure it with a different "real" address (ex: hotmail) to confirm the behaviour.
Cheers,