Hi, I use the "Mailing list standard" aggregation

Views / Message List / Aggregation / Mailing list standard

I love to browse all the message related to the same conversation in one place...
but in Kmail I partially achieve this goal:

a thread shows only the messages of the current folder.
That means if I open the thread from "Inbox" folder I see only the received messages.
To watch also the messages I sent I have to move to Sent folder, search the thread and the open it.
If I archive some messages of that conversation in a folder named "Customer", open the thread from there, I can't see all the messages hosted in Inbox and Sent.

Consider also the case I want to remove all the message related to the same conversation/thread.
If I remove the thread from the mailbox I still have to search for other messages in Sent and maybe other folders.

My suggestion is to always show all the thread messages, despite the folder I'm browsing.
Also the actions made on the thread shall apply to all the messages, despite the folder I'm browsing.

This approach is used by Gmail and Zimbra (Classic UI), Carbonio and probably other products.

You may prefer not to change the default behavior in Kmail to avoid confusing historical users, but you could make it optional.
Honestly, that's a very important feature for my daily use.

Thanks in advance!

Let me know what you think about.