How to group emails from the same correspondents?

I am wondering what's the best way to group emails from the same correspondents and have them sorted by the number of emails.

I often have some promotional emails and some newsletter emails, and sorting by the number of email from the same correspondents would be the quickest way to reduce unimportant emails for me. Or if there's a better way to group unimportant emails, please let me know. I tried writing some rules, but ended up having too many of them.

Thank you