Old thread, but maybe I can help others...
I'm guessing it's due to the fact you:
1. Have a DNS failure, and it's retrying to make a connection.
2. An ALM (alarm) condition is present, and it's notifying you of the condition!
Find the right DNS numbers for either the Primary or Secondary setting, and/or clear the alarm condition to see if the constant notifications go away.
WyreNut