Recently I installed my Kubuntu anew. The folder ~/.local/share/local-mail had been without files, so I did not back it up. Instead, the folder ~/.local/share/.local-mail.directory had all my mails so I did back this folder up.

In my new kmail (kmail on my new kubuntu installation), I this email-folder by adding it as a Maildir source: "Configure Kmail" -> "Network" -> "Receiving" -> "Add" -> "Maildir" - this worked.

However, I also have two even older maildir-email-folders I had saved on my computer and I would like to add as well by doing the same thing, but this does not work: The sources are visible in the left kmail-panel where the folders are displayed, but no subfolders and/or emails are displayed in them.

I can not see any apparent difference in folder structure between those oldest two maildir-folders and the last one I am able to include. What should I do?

Do you get any errors in the terminal or in .xsession-errors if you try to access those Maildir folders?

What I found out is this:

For the local folders I have (as many others as well, I'm sure) ~/.local/share/local-mail for the top-level-folder of the Lokal Mails and ~/.local/share/.local-mail.directory for the subfolders. That makes ~/.local/share/local-mail a maildir-folder and ~/.local/share a folder that "contains maildir folder". This definition of "... is a maildir folder" and "... contains a maildir folder" is interesting to me, because these wordings are displayed when I am about to choose one of them as a email source. In the case of the Local Mails I am using ~/.local/share/local-mail - maildir folder - as a source.

It turns out, that the source folder for my old mail (of my last kubuntu installation) is a folder that "contains maildir folders" and is properly included. However, my even older email archives (say ~/myveryoldemails) are not correctly included if I include ~/myveryoldemails. Instead I have to move ~/myveryoldemails to ~/.myveryoldemails.directory, make a new folder ~/myveryoldemails containing the three (empty) folders cur, new, tmp and finally include ~/myveryoldemails as a email resource.

As one may notice, kmail's behaviour towards my very old emails corresponds to it's behaviour towards the Local Mails, but it does not correspond to kmail's behaviour towards the old, but recent mail folder. What is that all about? What is going on here?


@einar: How am I supposed to access my mails via the terminal, or do you mean I should open kmail via the terminal and see what the output of the terminal is, when I try to access the mail via kmail?

Yeah, start kmail from a terminal, then try to access one of the folders with issues, and see if it throws out error on the terminal.