I’m working from home today to take care of my husband – he just had some wisdom teeth removed that he should have had pulled ages ago. He kept putting it off – and of course, it just got worse. Well, email is like that too. If you ignore it, it’s just more painful when it comes time to pull it all out of the inbox.
All of these steps help you organize and manage your Inbox and key tasks, but they don't get you out of spending time to review and respond to your mail.
Depending on the amount of mail you receive and its priority, think about scheduling time daily or at least weekly to go through your Inbox and respond to, file, and delete messages. I have set up Monday as ‘Meetingless Monday’ so that I can have time in the beginning of the week to get administrative tasks like this done. It doesn’t always stay a meetingless day, but by blocking it out as ‘out of office’, I get less meeting requests for that day.
During your email review time, take note of any newsletters and mailing lists that you never read. Then unsubscribe from them. You could just filter them to the Deleted Items folder, but you're better off just taking a moment to cancel unwanted subscriptions.
As you review your messages, you also may detect new patterns of mails that you could filter by a making a new Rule. Make a note of it but don't interrupt your flow too much. Save any rule creation, refinement, and side tasks for the end of your scheduled time so you put the focus on answering and managing your mails first.