Hello alussier1,
Welcome to the QuickBooks Community! It's great to hear that the firm you're working with is helping manage client books through QuickBooks Online Accountant. The My Accountant tab in your client's books, or the Work tab on the QBOA side, is a fantastic option for working with your client. I can see how the firm owner getting emails every time something happens might not be ideal, and I'm happy to help you with this.
On the Work tab, there's a link at the top called Notifications. I recommend having the firm owner click that link, which will take them to the Company settings in the QBOA account. They should be on the Notifications tab, where they can toggle which emails they received by clicking the pencil icon, checking or unchecking the options as desired, then clicking Save.
At this time, there isn't a way to fine tune the notifications where they could go to someone else, for example. Although the settings do give the option to Update the email, it means to update the email for the firm owner. I recommend leaving some feedback for the product development team about this to let us know what we can do to enhance the options for this section. Here's how: How do I submit feedback?
For your reference, here's an article about using the Work tab in QBOA: Collaborate with clients using the Work tab. It sounds like your client knows the My Accountant tab pretty well, but here's an article you can share with them as well if you'd like: How to use the My Accountant tab
I hope that helps. :) Have a great week.
