Deleting Mail

I’m clicking on a Mail , it was opening on right sight. When i delete this with the del-buttom, it was deleted and the next mail is on left side in use and openig on right side. When i delete this mail by clicking the del-buttom, all the mails on this day are marked, and will be deleted by clicking OK.
This is not a god function.

Hello Juergen,

I have tried to reproduce the issue you described, eM Client offered to delete whole group of messages only when I clicked on that specific day/week above the messages.  
Please be more specific about steps you have made or perhaps provide screenshot of that behavior if it is possible.