I am concerned that my Kmail may be cursed.
I have set up my two email accounts ok, GMX and Live/Hotmail. I receive via POP and send for these accounts without issue.
Kmail is set to put new mails in the Inbox in Local Folders, which it does.
When I move a message from the Inbox to any other folder it moves to that folder ok.
I return to the Inbox and the moved message re-appears there! The moved mail is still in the folder I moved it to so it seems Kmail is creating a copy (zombie?) email back in the inbox.
It makes no difference whether I drag and drop or right click and move using the folder tree.
I have no filters set. I have tried ticking and unticking 'Leave Messages On Server'. Tried removing emails from the online inboxes. I have tried everything I can think of and searched online.
This issue only seems to apply when moving emails from the Inbox. If I move mails between other folders it doesn't occur.
I have used Kmail in the past and never experienced this issue. It doesn't happen in Thunderbird, which I also have installed. But I prefer using Kontact/Kmail for the integration and features it offers.
This is a new install of Fedora 16 64bit with KDE 4.8.1.
If anyone can help me exorcise my Kmail of this curse I will be eternally grateful.

The symptoms on my install are somewhat similar in that I can't use the "delete" commamd on email as most email removed that way from local mail folders just returns (as unread mail). If I 'move' the mail to a local folder it stays there, so what I do is to move all the mail I want to delete to a folder named 'delete' and manually remove all the files in the folder once a week or so.

Recently I saw some spam that have been automatically expired away return, I hope that's not starting some trend.

Qt: 4.8.0
KDE Development Platform: 4.8.1 (4.8.1)
KMail: 4.8.0
Virtuoso Open Source Edition (multi threaded)
Version 6.1.4.3127-pthreads as of Mar 18 2012