[thefisola]

Filters only affects new incoming emails. If that's your intention, then that works perfectly. Of course this also means you never want to see a newsletter in your Inbox.

In cases where you want to mass delete older emails that you previously subscribed to, you might find InboxPurge useful.

[ncocacola]

You can apply filters to older emails.

[thefisola]

Oh interesting, didn't know this