Notification symbol missing at eM Client Logo in Task bar

When using Windows 7 I had a “double” notification when receiving new emails:

  1. I got a letter symbol on the right in the system tray (with sound).
  2. I also had a letter symbol on the yellow eM Client Logo on the minimized taskbar-app. This one disappeared when I maximizied the eM Client program to check the incoming mails.
    Since using Windows 10 I miss the symbol on the yellow eM Client Logo:

I already checked settings (Settings > Notifications), where you can choose to get popup, notification in system tray and/or sound. 
I did not find any setting to reactivate the letter-symbol on the logo nor did I find any information in the internet or in this forum (I hope I didn’t overlook something).

Does anyone know how to get that letter-symbol back?
I really liked to look at the taskbar with all those programs, seeing a letter on the logo telling me there is new mail. 

When taking the screenshot, I realized the problem:
I have the windows-setting “small symbols”. When I use “tall symbols” (search-bar white) the symbol appears as white letter. When using “small symbols”, the letter-icon does not appear. 
There you go:

That’s sad. I guess eM-Client has not influence on the appearence, as it seems a Windows-problem?