Would be nice to have a way to create a folder like «Thread», which would show all messages by thread from the specified folders, whilst still keeping the original messages in their places — e.g. incoming in «Inbox», sent in «Sent». Reproducible: Always Exist a workaround to force KMail to move sent and inbox into the same folder, but it isn't really nice — what's the point then to have separate folders? Things are even worse if you have multiple accounts, and want to see all messages in a single folder, whilst keeping them in the original places/servers. I'm sorry if that actually could be done already — then, if you provide the details, this request would still be useful, as someone would find it up from a search engine when needed.
As an example, this is what the Zimbra client does. For every message in a folder it shows the whole thread, including messages in different folders.
(In reply to Constantine from comment #0) > I'm sorry if that actually could be done already — then, if you provide the > details, this request would still be useful, as someone would find it up > from a search engine when needed. You can use merged views. I.e. just select multiply folders that you're interested in. But, as it pointed out in discussion[1], it would be great if it would be possible to include some folders(i.e. sent) by default. Or even if it possible to specify in the folder directly, what other folders should be used. Like if I have a separate folder for mail list, I do not want to include my "Sent" folder, since my message would be also delivered to that folder. [1] https://forum.kde.org/viewtopic.php?f=20&t=98574
Seems to be solved in KDE Applications 18.12.0¹. I am not sure why it wasn't marked as such though, but probably it was just forgotten. 1: https://pointieststick.wordpress.com/2018/09/16/this-week-in-usability-productivity-part-36/