I have quite a few portals running AF and a common issue I get is that email notifications seem to work sometimes, then just stop. No recent upgrades or anything...

This is the closest KB article we have: http://www.activemodules.com/active...fications/

The only things I could think are if you are using the Mail Queue and the scheduler stops for some reason. Or your mail server is refusing the connection.

When the issue occurs check for errors on DNN and on the mail server.