Mail app doesn't notify new email on Mac mini

From what you’re describing, it sounds like the Mail app isn’t checking for new emails unless you open it, and you're no longer seeing the badge count on the Dock icon either. That usually means the app might not be refreshing in the background the way it used to.

While it’s true you don’t have to manually “allow background activity” for Mail, certain settings can cause how often it checks for mail or whether it stays active in the background at all.

It’s also possible the account settings got changed slightly, like if your email is set to fetch manually instead of automatically.

Or sometimes Focus modes, notification settings, or even syncing across devices can affect how and when you're alerted.

It’s probably not a fault with Sequoia or your iPhone specifically, more likely a small setting that just needs adjusting.

Once it’s sorted, the Mail app should go back to quietly doing its thing in the background, letting you know when something new comes in.