I've added an event to the calender which i've recived via an E-Mail in KMail. I'm not the organizer of this event. It has the E-Mail address of an mailing list as participant. When i tried to remove the reminder settings in this event, KOrganizer asked me if i really want to do this as the event will get out of sync with the organizer. I clicked yes and KOrganizer automatically send an E-Mail to the mailing list with the "From:" address the address of the original organizer. It didn't ask for any confirmation. I consider this a serious bug. One solution to this problem would be to ask the user for conformation on any E-Mail that KOrganizer intends to send. Another one would be to send a the changes just to the original organizer as an suggestion or something. But even in this case some mail window should pop up so that the user can enter some sentences why he suggests this changes.
This bug has only been reported for versions before 4.14, which have been unsupported for at least two years now. Can anyone tell if this bug still present? If noone confirms this bug for a Framework-based version of korganizer (version 5.0 or later, as part of KDE Applications 15.08 or later), it gets closed in about three months.
Just as announced in my last comment, I close this bug. If you encounter it again in a recent version (at least 5.0 aka 15.08), please open a new one unless it already exists. Thank you for all your input.