KMail retrieves the same already retrieved mails two, three, four times ...

On one of my computers, KMail every day retrieves again the same mails that are already retrieved and not yet deleted in the provider’s POP3 mailbox. This forces me to do a “delete double messages” operation a few times a day. This has begin recently, about a week ago; before, I never experienced it (and I use KMail since 20 years!), and neither on my other computers. How can I stop this nasty habit? Thankx for any suggestions!

While it is of course possible that it is your Kmail that does not act as intended, have you ruled out that the mail-server side works as intended, deleting mails that are retrieved by the POP3 client? When the server does not remove them, the client will find them every time again.

And of course did you check the Kmail configuration of the user:
configure Kmail > Accounts > Tab: Receiving > select the account and click Modify;
on pop-up Tab; Advanced > POP Settings; Leave fetched messages on the server, checked or not?

Possibly an Akonadi issue?

 > akonadictl --help
Usage: akonadictl [options] start|stop|restart|status|vacuum|fsck|instances
Akonadi server manipulation tool

  start          Starts the Akonadi server with all its processes
  stop           Stops the Akonadi server and all its processes cleanly
  restart        Restart Akonadi server with all its processes
  status         Shows a status overview of the Akonadi server
  instances      List all existing Akonadi instances
  vacuum         Vacuum internal storage (WARNING: needs a lot of time and disk
  fsck           Check (and attempt to fix) consistency of the internal storage
                 (can take some time)

  -h, --help         Displays this help.
  -v, --version      Displays version information.
  --instance <name>  Namespace for starting multiple Akonadi instances in the
                     same user session
  --verbose          Make Akonadi very chatty

  command            Command to execute

For a first attempt, try “akonadictl fsck” and then “akonadictl vacuum” and then “akonadictl fsck” again.

  • The following “fsck” usage helps to notice an occasional database issue –
 > akonadictl fsck 2>&1| grep -iE 'found|no RID'

To repair this situation, you’ll need the “akonadiconsole” tool provided by the Package “akonadiconsole”.

My other computers doe not have this problem, with the same mail provider …

I always leave the messages on the server because I have 6 computers and I don’t want to deprive the other computers from getting all the messages. Once in a month or so, I delete the messages on the server. I never had any problems with that, and on my other computers there is no problem either, Kmail knows which messages it already has retrieved and does not retrieve them another time. I have this problem only now since a week, on one computer.

Many thanks! I’ll try to use akonadiconsole to repair the situation. I will report how it worked out …

I think the problem has gone away now. I used akonadiconsole, and found good advice here: I was able to remove all “dirty” messages without remote identifier, which cleaned up KMail’s database and made it possible again to remove the double messages in every folder. Thanks to all of you for your good advice!