kmail "невозможно сохранить загруженные письма. не удалось добавить элемент"

После загрузки сегодня невозможно скачать мою почту. Я получаю сотни всплывающих окон: "Не удалось сохранить загруженные письма. Не удалось добавить элемент"

В моем / доме нет проблем с UID или разрешением. Запуск kmail (kmail2 5.4.0) из оболочки дает мне много повторений первых блоков ниже:

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 ""

Я сделал перезапуск akonadictl, а также fsck и вакуума (много сообщений при этом): без изменений.