Status icon checking for new mail
Mail Notification is a status icon (aka tray icon) that informs you if
you have new mail.
It works with system trays implementing the freedesktop.org System
Tray Specification, such as the GNOME Panel Notification Area, the
Xfce Notification Area and the KDE System Tray.
There is no official package available for openSUSE Leap 15.4