I haven’t given it a go again, TBH.
The Mac Mini is in need of some serious TLC, probably through the Apple Helpline (issues around FileVault never finishing - thus not allowing TM backups at the moment) – so want to get that sorted first before going back to tackle the Mail Rules again.
Well, after a long, frustrating road dealing with email, not only have I renewed my SaneBox subscription, but finally given up and returned to Apple mail.
Even though it isn’t the nicest to ok at, it is the only one that works the way I need. AirMail and Spark have nicer interfaces, but failed on other fronts not worth going into here.
So, clearly I am a hypocrite! Hurray!
You are no hypocrite. Hypocrites pretend to be something they know they are not. That is not you. 
That said, I too have defaulted to Apple Mail. I don’t want another subscription so I have created good cloud-based email rules so they get applied to all devices.
Thanks! I use spark and missed this feature!
I use sanebox, but it filters my mail after I’ve already gotten a notification. Any fix for this?
I’m using Fastmail btw.
Thanks for this post. I had forgotten about the power of rules in the last couple of years since my job changed. I’m against folders (everything is inbox, archive, or trash), but I did set up flags for Action, Read Later, and Waiting on and set up some rules for those. Much appreciated!
I tried the free trial of Sane Box and that’s as far as I made it, I didn’t find it very useful.
This always annoyed me too but the way SaneBox works, there’s not much you (or they) can do. SaneBox “listens” your inbox to see if new emails arrive and then moves them based on your SaneBox settings. SaneBox is pretty quick but not instant. Email clients, including fastmail’s webpage, notify you the moment an email arrives, before SaneBox has a chance to move it, hence the notification. In other words, you and SaneBox get the notice about a new email at the same time.
You’re not asking about iOS but the following is an example of several help articles where SaneBox proposes workarounds but they may not be satisfactory because you need to disable notifications for all but your most important recipients:
Gave SaneBox another try…and quit again. No added benefit for me. If it included a spam filter, it might be worth it. So, I still have to run a spam filter (SpamAssasin) to keep the worst trash out of the loop. And after de-spamming the mail, SaneBox does it’s trickery.