In order for a user of the ISN to be able to create and send Mass Emails, their ISN user profile needs to have the Mass Email Access setting enabled.
Navigate to Administration -- User Administration, and then click on the Actions drop down for the user, and select Edit:
Scroll to the bottom of the page and select Owner Access--> Mass Email Access:
If you have any questions about this process please let us know! You can reach us by chat, email at email@example.com, or phone at (800) 700-8112.