After trying Mailbird for a couple of days it was crystal clear to me that it delivers!

My only issue is that I can't connect free Protonmail accounts, but this is something that doesn't depend on the Mailbird team as far as I can tell - it's that Protonmail does not allow free accounts to be connected with email clients (kindly correct me if I'm wrong).

I would love to see this product actively developed over the next year and more apps to be added. Especially other apps that have been showcased here on Appsumo, such as Nifty.
I hope that the team takes that into account, but I have to say that everything seems super smooth and fast.
Also, email tracking works perfectly.

Very happy with my purchase!