What are you using for the email engine (Administration -> Notifications)? Did you check the error logs?

As I said "Have tried email plugin and scheduler." There is nothing on email in the logs. There are only 2 entries and don't look to be related to email. The email test works okay.

Set it to mail plugin, make sure alerts are enabled (Administration -> Notifications) and check that your profile settings allow you to get emails and your own changes. Once done, view an item and "watch" it. Add a comment, do you get an alert?

Okay that's the problem. In 2.2.6 we didn't have to do anything extra to get email. How can we set this up so that we get email on every issue? It seems tedious to go through every issue and set the "watch" setting. How can we make sure every new issue from now on is watched by everyone?

You don't need to do that, it was just a test to see if it is working. If you did get an alert then all you have to do is enable alerts for the project(s). In each project click on the "email alerts" link (top right) to configure your alerts.

I apologize for being so uninformed. The alerts setting you describe was already configured for alerts on everything.

I have 26 watch, 33 my work, but there are 288 items. I still don't think I am getting the email alerts on all of these. What are the requirements to get alerts? Do all 288 items need to have "watch" set, or be "my items" to get alerts? Many of these items came over during the upgrade. Is this why they are not marked as watch? There are only 2 of us using gemini, so I need to always get email on every issue.

You don't need to watch them to get alerts. If you send us your database (support at countersoft dot com) we will look into it.