Taskbar Envelope Won't Go Away

I have no new messages, and the little black “new mail” envelope appears on the emClient taskbar icon.

Even after I close the application…

Funny, I have the opposite problem – it never shows the black envelope anymore when I receive new mail (I think since I updated to 9.1).

To be clear, the envelope in the system tray goes away when I close the program; it’s the black envelope on the taskbar icon (I have emClient pinned to taskbar).

OK, it seems that if I OPEN an Unread mail in EACH of my accounts, it will go away. Opening one in just one account, or deleting unread emails, will not make it go away.

It’s just weird that it stays after closing the program…