Thanks.
I am actually using the local server to archive messages in a centralized location. I did intially consider IMAP more appropriate than POP3 since the POP3 will always download the messages from a server to the local client but now with a second thought, this is perhaps for the inbox only. Maybe POP3 is useable in my application.
I did also discover the following bug report which explains my issue:
https://bugs.kde.org/show_bug.cgi?id=291143
Now I know that my version has the bug reported above. I am not sure if I will update to the latest versions of software at this point. Maybe I try POP3 as suggested above.
One issue remains, however: the Akonadi keeps posting disturbing Notifications on my KDE desktop in regular intervals. I do not know how to clear the error Notification without stopping the services, which I do not want to do. Any advice on that ?
Mika