In the Outlook web app settings, you can enable notifications for messages (emails) and for events. I just have notifications ticked on for events so I'm made aware of calendar invites for those meetings at work.
Outlook web app on Brave works well too. I think I needed to install Google Play Services first so Brave can push notifications. In fact, I just have Brave installed for this purpose, usage of my work emails. I use Vanadium and Brave Beta for surfing other sites.
When I was first making the switch from stock Android to GrapheneOS a few years ago, I re-evaluated my approach and usage of essential apps. On stock, I was using the official Outlook app for my work emails, as I 'needed' those email notifications, or so I thought. When I switched to GrapheneOS I went for the web app version of Outlook, which was better for privacy indeed. I remember for some time I never received email notifications, as there was an issue with the Outlook web app (which later got fixed by MS). But hey this was a blessing in disguise - like what Michiel said. It can be good for your mental health not to be notified as soon as a work email comes through. I just check the web app version periodically for emails.