Mail that comes in is first as usual in the inbox - I am using POP3. But after some time it can happen (it might also happen at once) that Kmail somehow sets subject, sender, receiver, date to "Unkown". For some mails this information is just "Unknown" in the Message List and fully displayed, when I open the message. For other mails the information is "Unknown" either way. Going online and looking at the messages of the server, the messages are normal messages. Now it even seems that Kmail is setting emails I am clicking on to "Unknown".

It seems I am having the issue mentioned in http://linux.derkeiler.com/Mailing-List ... 00457.html
and it seems to be related to the bug https://bugs.launchpad.net/ubuntu/+sour ... +bug/50039 - but it is very old and supposed to be of Kmail1.

I considered following https://userbase.kde.org/KMail/FAQs_Hin ... osing_mail
but when I click on the folder or on "Folder" from the menu, I don't get anything like "rebuild index".

What can I do to fix this issue?

PS: Why is Kontact/Kmail soooo buggy?
PPS: Why is there no decent documentation to modern Kontact, or did I miss it?

Are the message headers (push "V" to view them) all right even in these "Unknown" mails? It implies some sort of failure to parse.

In order to clear the cache, run "akonadiconsole", move to the "Browser" tab, right click on the folder and select "Clear Akonadi cache".

einar wrote:Are the message headers (push "V" to view them) all right even in these "Unknown" mails? It implies some sort of failure to parse.

Thanks for answering. No they are not fine - there is nothing in there.

einar wrote:In order to clear the cache, run "akonadiconsole", move to the "Browser" tab, right click on the folder and select "Clear Akonadi cache".

Could you explain a bit, please:
a) What am I doing here?
b) Why should this help?
c) What are the dangers (for example regarding losing my original mail in my maildir-folders)?

d) Also: Do you know why mails are deleted if I click them?

The step I outlined purges the information stored in the cache and on next access the information will be retrieved directly from the "data source", namely the folder. It should be safe, but you may want to back up data if you prefer. It should help because if Akonadi has wrongly cached data, you'll get it fresh.

And about "d", this should not happen. Are you sure it's just not a viewing preference (unread mail vs all mail)?

And about "d", this should not happen. Are you sure it's just not a viewing preference (unread mail vs all mail)?

Yes, I am positive.

Strangely enough it seems the problem solved itself... no more mails are being deleted. I am using git over my mails now, so that this can be prevented - at least partially - now.

It just happened again. This time I realized something: The partition on which my mails are was full. Is it possible that this can lead to the observed effect?

I wonder if this is a side effect of something else... if for any reason this occurs again, please note down the steps that you did, so that a proper bug report can be filed.

It just happened again.
The exact steps are:

1. Everything is as normal in the last session.
2. I go into Kontact.
3. Suddenly there are a lot of E-mails displayed with Unknown Date, most of which have everything unknown (sender, receiver, and a deleted body), some have only the date unknown.

The is a pretty thin description, but nothing else was done by me. This time my partitions have lots of space.

I can see that some of my messages I did answer to, so obviously they were not spam or anything like that. This is not funny. Can I retrieve the lost emails?