Related: https://forums.mozillazine.org/viewtopic.php?t=3079875 I used to daily version 52, and this would allow you to in windows set it to show the new mail tray icon, but hide the normal tray icon. Seems since the introduction of mail.biff, this was unified and it's no longer seperate entries in the windows Taskbar Settings -> Select which Icons appear on the taskbar menu. Attached image shows the 2 old entries, and the singular new one which is the same, unread notification or not in the tray icon. I can only select/deselect one thunderbird entry here, which just toggles if it's there at all or not. I do not wish to see the normal tray icon. I wish for the tray icon to show in my tray bar when there's a new/unread message. This seems to be a thing that was regressed and fixed in v68, and then became an issue again with biff's introduction in v91 forward? Thanks for your time.