However, I never found the ease of achieving Inbox Zero like I did with Mailbox. I don't think anything has gotten close to that, and I still miss it as I'm pretty sure it was the perfect mail app.
Polymail's read receipts were very useful, even after they got blurred out, it was still great to get the "Someone read..." notifications.
Signatures were so clean and synced across my devices without any problems.
Dislikes about Polymail (and stopping me from switching to a paid plan) - hard to refresh inbox (I still don't know how to force this apart from quit and reopen on Mac), the fact that it is not a native app (Electron or similar), weird behaviour when tapping a new push notification on iOS (sometimes the previously read email would stay open), just general non-native feelings.
I can't really justify the price and I never used any of the enterprise features, we use Slack for all that stuff, plus I am not a salesperson and if I were in the founder role of selling hard and raising money again I would probably invest in Superhuman.
As a thought, I will probably switch to Airmail as its $10 a year price point for a passive email user seems just right.
Best of luck with growing Polymail and good on you for giving it a new lease of life :)