SUMMARY As the title says, sometimes kmail hangs and never displays the content of the messages. Emails are on the gmail. OBSERVED RESULT Kmail says: Unable to fetch item from backend (collection -1): Unable to retrieve item from resource: did not receive a reply. Possible causes include: the remote app didn't send a reply. EXPECTED RESULT Displayed mail. SOFTWARE/OS VERSIONS Arch Linux, latest KDE, Nvidia driver.
Workaround I found was to stop akonadictl and then restart it. So the problem seems to be (again) akonadi.