New email notification missing in a Konsole 20.12.3 (oldstable Debian)

Hello, inside Konsole I do not see any CLI notification of a newly arrived email, which I am used to seeing on a headless servers - it usually appeared after executing some command.

I can see that it appears on a default CLI (Ctrl+Alt+F5, then Alt+F7) but not inside Konsole app (the app which shows a terminal).

It looks like an issue of a KDE or Konsole app. Do you have any idea to fix this?

Debian 11 bullseye (oldstable) with KDE and konsole 20.12.3

KDE Plasma Version: 5.20.5
KDE Frameworks Version: 5.78.0
Qt Version: 5.15.2
Kernel Version: 5.10.0-30-amd64
OS Type: 64-bit