Version:           4.7 (using KDE 4.7.0) 
OS:                Linux

I have two akonady resources: a mixedmaildir resource pointing to
~/.kde4/apps/kmail/mail and a maildir resource pointing to
~/.local/share/local-mail (the first one being my backup, the second one my storage for local mails)

Due to mail loss I recently had copy a lot of mails from the mixedmaildir resource to the maildir resource.

When I copy a mailfolder by drag and drop within kmail, it seems that the folder and the mails in the folder are being copied as expected, but when I try to open one of the mails, only the mail header (From:, To:, Subject: and so on) will be showed, but no content.

Looking for the mails in the filesystem (in one of the subfoders of ~/.local/share/.local-mail.directory/), I see that actually only the mailheaders have been copied.

Strangely enough, this only "works" if the mails to be copied are selected automatically, either by copying a whole folder or by using Ctrl-A. If the mails are selected manually one-by-one, they are copied as expected.

Even more strangely, when I delete the copied messages and then copy them again, this time it works as expected (the whole mails including their content are copied).

This is reproducible on my system, even after restarting the computer: Copying the mails, the first time only the headers are copied, afterwards the whole mail is copied.

As this bug potentially causes data loss (when moving the mails instead of copying), I consider this a severe bug.

Reproducible: Always

Steps to Reproduce:
1. Create a mixedmaildir resource pointing to an existing kmail mail folder.
2. Create a maildir resource pointing to e.g. ~/.local/share/local-mail
3. In Kmail, Automatically select a bunch of mails in the mixedmaildir resource, either by selecting a folder or by using Ctrl-A
4. Drag-and-drop the mails to the maildir resource, selecting "copy"
5. Select one of the copied mails in the maildir resource

Actual Results:  
Only the mails' headers will be shown.

Expected Results:  
The whole mails should be copied, not only their headers.