If have multiple emails in my inbox or in any folder in my imap account. I start reading the emails and go to delete one or move the one I read to the trash and all the emails in that folder disappear. To view the rest of the emails in that folder, I have to click to another folder and then back to that folder again. They don't actually go anywhere. I just can't see them until I click off and back on that folder. It doesn't happen all the time and I have been trying to figure out a pattern but so far, I am unable to. It does happen often enough to be very annoying. Reproducible: Sometimes
I have this same problem with kmail 4.14.1 on kubuntu 14.10 with an imap account and a separate folder I've set up to receive certain messages after filtering. It does not appear to happen to my primary (IMAP) inbox but always to the separate folder that I have set up.
This bug has never been confirmed for a KDE PIM version that is based on KDE Frameworks (5.x). Those versions differ significantly from the old 4.x series. Therefore, I plan to close it in around two or three months. In the meantime, it is set to WAITINGFORINFO to give reporters the oportunity to check if it is still valid. As soon as someone confirms it for a recent version (at least 5.1, ideally even more recent), I'll gladly reopen it. Please understand that we lack the manpower to triage bugs reported for versions almost two years beyond their end of life.
Confirming this issue with Kmail 5.2.3 and Akonadi 5.2.2 on Ubuntu 17.04. Also I've got the same problem some years ago with KMail on openSUSE.
I still see this problem in kde 5.2.3. Specifically it happens in an imap folder that is NOT my inbox folder, and if there are multiple emails in that folder, if I click on the bottom most email (vertically) and delete it it doesn't happen. If however I click on any entry above the bottom then the rest disappear and I have to click on another folder and go back to get my emails to reappear.
Here is video with this bug: https://youtu.be/FjgeKne1UY4
Thanks for the update; setting status.
Bug stills exists in kmail2 5.10.1 (Manjaro). For me, it seems only to be triggered when there is only one message left in the list.
I confirm this as well, under Arch and kmail 5.16.0. I have a gmail inbox, and when I delete a message in it all other messages disappear. I usually have just a bunch of messages as I archive or delete them as soon as possible, so the ones that disappear are usually others that I need to read, and as mentioned by others I have to switch folder to see them again. It's very frustrating :(
I receive more than 1000 emails every week. I can confirm that this bug stills even in KMail 5.22.3 (22.12.3) and is frequent occurance for me because I usually delete email starting from the bottom in various folders -- which are populated with server side filters on the inbox. This is very annoying. Please share if there is anything I can do on my end to help with this. Thanks.
*** Bug 318049 has been marked as a duplicate of this bug. ***
*** Bug 343770 has been marked as a duplicate of this bug. ***