Encontrei uma solução para o problema aqui: link
Após a inicialização hoje, é impossível fazer o download do meu e-mail. Eu recebo centenas de janelas pop-up com: "não é possível armazenar emails baixados. Falha ao anexar item"
Não há nenhum problema de uid ou permissão no meu / home. Iniciar o kmail (kmail2 5.4.0) a partir do shell me dá muitas repetições dos primeiros blocos abaixo:
org.kde.pim.pop3resource: ============== ERROR DURING POP3 SYNC ==========================
org.kde.pim.pop3resource: "Unable to store downloaded mails.\nFailed to append item"
WARNING: Phonon::createPath: Cannot connect Phonon::MediaObject ( no objectName ) to Phonon::AudioOutput ( no objectName ).
org.kde.pim.akonadiserver: DATABASE ERROR:
org.kde.pim.akonadiserver: Error code: 1292
org.kde.pim.akonadiserver: DB error: "Incorrect datetime value: '0000-00-00 00:00:00' for column 'datetime' at row 1"
org.kde.pim.akonadiserver: Error text: "Incorrect datetime value: '0000-00-00 00:00:00' for column 'datetime' at row 1 QMYSQL3: Unable to execute statement"
org.kde.pim.akonadiserver: Query: "INSERT INTO PimItemTable (rev, remoteRevision, gid, collectionId, mimeTypeId, datetime, atime, dirty, size) VALUES (:0, :1, :2, :3, :4, :5, :6, :7, :8)"
org.kde.pim.akonadiserver: Error during insertion into table "PimItemTable" "Incorrect datetime value: '0000-00-00 00:00:00' for column 'datetime' at row 1 QMYSQL3: Unable to execute statement"
org.kde.pim.pop3resource: ============== ERROR DURING POP3 SYNC ==========================
org.kde.pim.pop3resource: "Unable to store downloaded mails.\nFailed to append item"
WARNING: Phonon::createPath: Cannot connect Phonon::MediaObject ( no objectName ) to Phonon::AudioOutput ( no objectName ).
org.kde.pim.pop3resource: UID list from server is not valid.
org.kde.pim.pop3resource: UID list from server is not valid.
org.kde.pim.pop3resource: UID list from server is not valid.
org.kde.pim.pop3resource: UID list from server is not valid.
org.kde.pim.akonadicore: Got a stale notification for an item which was already removed. 71893 ""
org.kde.pim.akonadicore: Got a stale notification for an item which was already removed. 71893 ""
Eu fiz o akonadictl restart, e também fsck e vacuum (muitas mensagens enquanto fazia isso): nenhuma mudança.