Especially the CVE notifications from software vendors so things get patches quickly. Important alerts are also tagged/colored so easy to spot quickly. Then I can quickly process the alert/notification messages, quickly sort/search, save anything that may be needed before removing clutter/noise messages.
So alerts/messages are divided by providers, root of inboxs are kept as close to zero unread as possible.
Use filter rules to sort messages to sub folders. Right now between the over a dozen accounts, about 32k unread (about 140k total at the moment, going back 20 years, only import things get kept more than a year), but I rarely miss any important messages, ticket system is always open along with monitoring systems (3 monitors so everything important is always visible at a glance while doing other activities).
