yesterday I decided to play a bit in Kontakt. I imported my e-mails and addressbook from Thunderbird, it all went good. In Kmail I created some subfolders for the old e-mails and this was OK too. Then I went to the addressbook and made quite a lot of updates in the data's (phone numbers, categories, new distribution lists,...) After one hour of work, everything was done and then I came back to Kmail and all my subfolders had disappeared! I can see them in Dolphin (.local/share/apps/local-mail or something like that) but in Kmail they are not visible and it is impossible to move new mails to these folders.
Any idea how I could correct this?
By the way, the distribution lists I created do not work, but it seems it is a known problem.