1 - Apply this workflow by Blake Robbins
https://medium.com/@blakeir/the-best-e-mail-workflow-no-extensions-needed-1eb296eaf069
2 - Unsubscribe for newsletters you don't read
3- Automatically send newsletters to a specific inbox without having them in the Primary Inbox. To do so, when you receive an email, click on the email, click on the 3 vertical dots and on "Filter Messages Like this". Then put the email adress in the From input, then Click "Create filter"

On the next popup, do these 3 steps.
- Click on Skip the Inbox
- Click Mark as read so you don't have an unread number
- Choose the Later Inbox you just created previously
To finish, click Create Filter.

From now on, all the emails coming from this newsletter will go directly to this inbox without cluttering your main inbox. Enjoy! I have using this workflow for a couple years and really like it.