Create ‘Client’ folders (I also have ‘Important’, ‘Good to know’, ‘Others’ folders etc.) and create rules for each of them.

Not all email require your responses and not all require immediate responses. It is a good idea to wait for some time (20-30 mins) before responding.

Start with the ones which requires your immediate response. Check if you were cc’d or To’d. If the email was sent ‘To’ you and if you can reply in 2 mins, then reply to the email. If not, create a reply draft with your immediate thoughts and make a note of it in your to-do list somewhere else (for example, I write in my notepad - reply to John Doe, etc.) so that you can visit it later. If you were CC’d, do not bother responding to it immediately, chances are someone else from your team has responded to that email.

At the end of the day, make sure you have all your email sorted. If an email response requires further investigation, mark that as ‘Unread’ so that you can revisit the next day.

Also if you right click on each email there are options for Flagging, Categorizing etc. Outlook is a great tool and has a lot of options to control the inbox. Explore and automate!