I get a notification that theres a new email in my spam folder. Then a bit later I get the notification for my inbox. Either kmail is copying the email from the inbox and putting it in the spam folder instead of moving it, or it gets the email, puts it in the spam folder, but then fetches it again and keeps it in the inbox? I'm not sure

Which version of KDE PIM are you using?

einar wrote:Which version of KDE PIM are you using?

4.9.1

Is this via POP3 or IMAP? I know POP3 filtering has still issues.

IMAP. This just recently started happening to me, but don't know since when or what changed.

akonadiconsole shows a spam email in my spam folder with id 63156, and the same one in my inbox as 63157.

Can you search through bugs.kde.org and see if the issue has been reported? There have been multiple fixes for filtering, but apparently not all cases were caught. The good news is that in about 2 weeks the whole KDEPIM group will gather for a development sprint, and we can expect quite a lot of fixes in a very short time.

Good idea. Seems someone reported one last week. They said its filters in general that dupes. They're also using Arch Linux, so I don't know if its distro specific; it might be since there can't just be 2 kmail users...