We ended up rewriting large parts of the code dealing with notifications. The user experience isn’t vastly different, but hopefully most of the annoying things that you had to put up with are gone now. Some examples:
When syncing a folder for the first time, the app no longer creates notifications. That’s a good thing. When setting up the app, you don’t want to get notifications for messages that are 2 years old but happen to be unread.
The app no longer creates notifications when you manually refresh the message list. However, you will still get notifications when manually refreshing a whole account or all accounts. This is so you don’t miss new messages in folders that aren’t currently displayed.
When displaying the message list screen, notifications for messages in that list are automatically removed. Previously, all notifications belonging to that account had been removed
In earlier versions, going back after opening a message via a notification would open the folder the message belongs to. Now the Unified Inbox is opened (if the message is part of the Unified Inbox).
Notifications for new messages are now restored when the app is restarted. That’s useful e.g. after a device reboot."
It would be amazing if the notifications really are "fixed". It's a fantastic app that has only been let down by the notifications. It happens, in my case to be linked to accounts I don't "check" regularly because they exist only for "important" emails. When I miss them, it can be a real issue for me.
I like K.9 but the notifications are extremely unreliable and I don't want to have to get into the habit of checking for mail.