Email can be challenging. But mastering it can transform your life and your ability to engage with what really matters.
The deck is so fucking unfairly stacked against us when it comes to email that if you sit back and think about it, you'll go crazy. So don't do that.
Instead, try the following strategies for handling email.
If you get a handful of emails a day that are just sales/offers from a business that you don't intend to buy stuff from, get on their unsubscribe list. While you're at it, search your inbox for other messages from same list and delete those too. You want to treat the inbox as a place of work, a place that can be reasoned about. There's no sense or path forward in attempting to reason about expired sales and the like.
Now that you've removed the noisiest offenders (e.g. marketing messages, "we've missed you" auto-mailers for things that you don't care about), you can go a level deeper: create rules to make the remaining mailings make more sense. If you know that every day you'll open your email to fifty automated notifications regarding other people's work status, and maybe between zero and two related to your own, maybe you should consider writing a filter so that the other people's stuff goes to a separate folder, but stuff related to you goes to the inbox.
Everyone is different, but you want to find your way to a sense of comfort that all of the emails are in the right place - the stuff that is most important stays front-and-center, and the other things fall to the periphery, further so the less critical they are to your work and decision-making.
You want to treat the inbox as a place of work, a list of things that can be reasoned about. Anything that requires no work or reckoning should be archived. You can find it if you need it, but until then, it's away from the 'workspace'.
Once you have appropriately pared down the inbox to things that you need to care about, you can commit yourself to treating the inbox like work. This means responding (or otherwise performing some action/work) where necessary and then archiving once that work has been completed.
People will say "I have seen such a change in Pat!1 I wonder what happened! Pat is just really responsive and gets things done."
"Pat" because the name is pretty neutral, innit?↩