I'm not sure if this functionality is already implemented on other platforms, but this relates to GNU/Linux. I've used Thunderbird on both GNOME and Sway and the experience is the same.
When a new email is received, I will get a notification for it. I was using Evolution for a very long time before this. I would often ignore the notification, switch to my Evolution window, and click the email. At that point, the notification would be dismissed.
On Thunderbird, if I ignore the notification, read the email, and delete it, the notification will still persist in my notification center on GNOME. The same is true on Sway with Mako (my notification daemon); it will continue to take up screen real estate even after I've dealt with the email if I don't explicitly dismiss the notification or wait for it to disappear.
I thought perhaps this integration was achieved because Evolution is tied closely into GNOME, but the same feature works perfectly well on Sway.
This is a very small feature which I never appreciated until I learned Thunderbird didn't have it. It's a great quality-of-life feature which, with any luck, would not be difficult to implement. It might even be a toggle, as some users may see the notification remaining in the notification center even after dealing with it as a feature (though in GNOME world, that's not how notifications are intended to be used).