How can I create a filter? I want all mail containing a specific word, e.g “Fedora” to not be included in the unified mail, and instead in a specific directory. I receive many such mails and the unified inbox gets cluttered. Can I use Google’s label function? Or something else?
This not a functionality of K-9. If you want to filter (or to be more precise: apply rules), you must configure them on your server.