Provide the option to enable notifications based on email performance (possibly set at org level or at mailing level). This would allow notifications to be sent by email, text or perhaps be displayed on the dashboard if a mailing has excessive spam complaints (< 1 per 1,000) or excessive opt outs (< .50%).

It would be handy as well if custom notifications can be established at the mailing level, or established at a user account level (notification is sent if mailing doesn't reach 22% open rate after 1 day, for example).