How do I prevent iPeer from sending emails (other than instruction notifications) to my agents

The best way to block emails from being sent to your agent is to configure this when you first add your agent to iPeer. If you didn't check this box when your agent was added, they have already received a couple of emails. 

You can block emails for any agent at any time. Find the desired agent in the Agents List, and click the icon to view the actions. Select 'Block Emails'.

You can always unblock  emails by following the same steps: