Mails deleted from Mail-Provider account automatically

[Betzejoe]

Steps to reproduce

1. Create connection to mail provider web.de with imap
2. Update app to v5.0.0
3. Wait for synchroinizing

Expected behavior

mails are synchronized with web.de account without deleting them

Actual behavior

Synchronizing emails deletes emails in provider mail account and in nextcloud mail.
emails are complete deleted - data loss. no possibility to recover.
Deactivated app to save for further deletions

Mail app version

5.0.0

Nextcloud version

30.0.0

Mailserver or service

web.de

Operating system

Linux 6.12.20+rpt-rpi-2712 aarch64

PHP engine version

PHP 8.2

Nextcloud memory caching

No response

Web server

Apache (supported)

Database

MySQL

Additional info

No response

[ChristophWurst]

Hi @Betzejoe! Thank you for the report.

Can you share more details of how the app deleted emails?

[ChristophWurst]

We've been running the pre-release of v5.0.0 for a few days with no such effect. Generally, I can't think of any section in our code that could cause this.

Please share all details you may have.

[ChristophWurst]

So far there are also no reports at https://help.nextcloud.com/search?q=mail%20order%3Alatest_topic.

[Betzejoe]

I updated the app and than emails get deleted by synchronizing. If you tell me which protocol files will help you please tellme and I will insert them

[Betzejoe]

Since 29.3. I frenquently get this errors. But this did not influence the email app and the email synchronization. Maybe this is not relevant or maybe this error leaded in relation to the upgrade of the app to the deletion?!:
[mail] Fehler: Cron importance classifier training failed: Call to undefined method Rubix\ML\Datasets\Unlabeled::numFeatures()
von ? von -- um 16.04.2025, 07:25:01

{"reqId":"spjQsumMZjoRpf3LGFGF","level":3,"time":"2025-04-16T05:25:01+00:00","remoteAddr":"","user":"--","app":"mail","method":"","url":"--","message":"Cron importance classifier training failed: Call to undefined method Rubix\\ML\\Datasets\\Unlabeled::numFeatures()","userAgent":"--","version":"30.0.0.14","exception":{"Exception":"Error","Message":"Call to undefined method Rubix\\ML\\Datasets\\Unlabeled::numFeatures()","Code":0,"Trace":[{"file":"/var/www/html/custom_apps/mail/lib/Service/Classification/FeatureExtraction/CompositeExtractor.php","line":53,"function":"extract","class":"OCA\\Mail\\Service\\Classification\\FeatureExtraction\\SubjectExtractor","type":"->","args":["*** sensitive parameters replaced ***"]},{"function":"OCA\\Mail\\Service\\Classification\\FeatureExtraction\\{closure}","class":"OCA\\Mail\\Service\\Classification\\FeatureExtraction\\CompositeExtractor","type":"::","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/custom_apps/mail/lib/functions.php","line":19,"function":"array_map","args":[["Closure"],[["OCA\\Mail\\Service\\Classification\\FeatureExtraction\\ImportantMessagesExtractor"],["OCA\\Mail\\Service\\Classification\\FeatureExtraction\\ReadMessagesExtractor"],["OCA\\Mail\\Service\\Classification\\FeatureExtraction\\RepliedMessagesExtractor"],["OCA\\Mail\\Service\\Classification\\FeatureExtraction\\SentMessagesExtractor"],"*** sensitive parameters replaced ***"]]},{"file":"/var/www/html/custom_apps/mail/lib/Service/Classification/FeatureExtraction/CompositeExtractor.php","line":52,"function":"OCA\\Mail\\array_flat_map","args":[["Closure"],[["OCA\\Mail\\Service\\Classification\\FeatureExtraction\\ImportantMessagesExtractor"],["OCA\\Mail\\Service\\Classification\\FeatureExtraction\\ReadMessagesExtractor"],["OCA\\Mail\\Service\\Classification\\FeatureExtraction\\RepliedMessagesExtractor"],["OCA\\Mail\\Service\\Classification\\FeatureExtraction\\SentMessagesExtractor"],"*** sensitive parameters replaced ***"]]},{"file":"/var/www/html/custom_apps/mail/lib/Service/Classification/ImportanceClassifier.php","line":408,"function":"extract","class":"OCA\\Mail\\Service\\Classification\\FeatureExtraction\\CompositeExtractor","type":"->","args":["*** sensitive parameters replaced ***"]},{"function":"OCA\\Mail\\Service\\Classification\\{closure}","class":"OCA\\Mail\\Service\\Classification\\ImportanceClassifier","type":"::","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/custom_apps/mail/lib/Service/Classification/ImportanceClassifier.php","line":402,"function":"array_map","args":[["Closure"],["*** sensitive parameters replaced ***",["OCA\\Mail\\Db\\Message",8866],["OCA\\Mail\\Db\\Message",8865],["OCA\\Mail\\Db\\Message",8860],["OCA\\Mail\\Db\\Message",8864],"And 155 more entries, set log level to debug to see all entries"]]},{"file":"/var/www/html/custom_apps/mail/lib/Service/Classification/ImportanceClassifier.php","line":193,"function":"getFeaturesAndImportance","class":"OCA\\Mail\\Service\\Classification\\ImportanceClassifier","type":"->","args":[["OCA\\Mail\\Account"],[["OCA\\Mail\\Db\\Mailbox",9],["OCA\\Mail\\Db\\Mailbox",11],["OCA\\Mail\\Db\\Mailbox",12],["OCA\\Mail\\Db\\Mailbox",14],["OCA\\Mail\\Db\\Mailbox",15],"And 5 more entries, set log level to debug to see all entries"],[["OCA\\Mail\\Db\\Mailbox",8]],["*** sensitive parameters replaced ***",["OCA\\Mail\\Db\\Message",8866],["OCA\\Mail\\Db\\Message",8865],["OCA\\Mail\\Db\\Message",8860],["OCA\\Mail\\Db\\Message",8864],"And 155 more entries, set log level to debug to see all entries"],["OCA\\Mail\\Service\\Classification\\FeatureExtraction\\CompositeExtractor"]]},{"file":"/var/www/html/custom_apps/mail/lib/Service/Classification/ImportanceClassifier.php","line":234,"function":"buildDataSet","class":"OCA\\Mail\\Service\\Classification\\ImportanceClassifier","type":"->","args":[["OCA\\Mail\\Account"],["OCA\\Mail\\Service\\Classification\\FeatureExtraction\\CompositeExtractor"],["OC\\AppFramework\\ScopedPsrLogger"],["OCA\\Mail\\Support\\PerformanceLoggerTask"],false]},{"file":"/var/www/html/custom_apps/mail/lib/BackgroundJob/TrainImportanceClassifierJob.php","line":72,"function":"train","class":"OCA\\Mail\\Service\\Classification\\ImportanceClassifier","type":"->","args":[["OCA\\Mail\\Account"],["OC\\AppFramework\\ScopedPsrLogger"]]},{"file":"/var/www/html/lib/public/BackgroundJob/Job.php","line":61,"function":"run","class":"OCA\\Mail\\BackgroundJob\\TrainImportanceClassifierJob","type":"->","args":[[2]]},{"file":"/var/www/html/lib/public/BackgroundJob/TimedJob.php","line":83,"function":"start","class":"OCP\\BackgroundJob\\Job","type":"->","args":[["OC\\BackgroundJob\\JobList"]]},{"file":"/var/www/html/lib/public/BackgroundJob/TimedJob.php","line":73,"function":"start","class":"OCP\\BackgroundJob\\TimedJob","type":"->","args":[["OC\\BackgroundJob\\JobList"]]},{"file":"/var/www/html/cron.php","line":162,"function":"execute","class":"OCP\\BackgroundJob\\TimedJob","type":"->","args":[["OC\\BackgroundJob\\JobList"]]}],"File":"/var/www/html/custom_apps/mail/lib/Service/Classification/FeatureExtraction/SubjectExtractor.php","Line":89,"message":"Cron importance classifier training failed: Call to undefined method Rubix\\ML\\Datasets\\Unlabeled::numFeatures()","exception":[],"CustomMessage":"Cron importance classifier training failed: Call to undefined method Rubix\\ML\\Datasets\\Unlabeled::numFeatures()"},"id":"67ff8eaa7998f"}

[mail] Fehler: Cron mail sync failed for account 2
von ? von -- um 16.04.2025, 06:55:06

{"reqId":"D1I6dMrCFtAfnVrrso8C","level":3,"time":"2025-04-16T04:55:06+00:00","remoteAddr":"","user":"--","app":"mail","method":"","url":"--","message":"Cron mail sync failed for account 2","userAgent":"--","version":"30.0.0.14","exception":{"Exception":"OCA\\Mail\\Exception\\ServiceException","Message":"Sync failed for 2:INBOX: Call to undefined method Rubix\\ML\\Datasets\\Unlabeled::numFeatures()","Code":0,"Trace":[{"file":"/var/www/html/custom_apps/mail/lib/Service/Sync/ImapToDbSynchronizer.php","line":133,"function":"sync","class":"OCA\\Mail\\Service\\Sync\\ImapToDbSynchronizer","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/custom_apps/mail/lib/BackgroundJob/SyncJob.php","line":93,"function":"syncAccount","class":"OCA\\Mail\\Service\\Sync\\ImapToDbSynchronizer","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/lib/public/BackgroundJob/Job.php","line":61,"function":"run","class":"OCA\\Mail\\BackgroundJob\\SyncJob","type":"->","args":[[2]]},{"file":"/var/www/html/lib/public/BackgroundJob/TimedJob.php","line":83,"function":"start","class":"OCP\\BackgroundJob\\Job","type":"->","args":[["OC\\BackgroundJob\\JobList"]]},{"file":"/var/www/html/lib/public/BackgroundJob/TimedJob.php","line":73,"function":"start","class":"OCP\\BackgroundJob\\TimedJob","type":"->","args":[["OC\\BackgroundJob\\JobList"]]},{"file":"/var/www/html/cron.php","line":162,"function":"execute","class":"OCP\\BackgroundJob\\TimedJob","type":"->","args":[["OC\\BackgroundJob\\JobList"]]}],"File":"/var/www/html/custom_apps/mail/lib/Service/Sync/ImapToDbSynchronizer.php","Line":282,"Previous":{"Exception":"Error","Message":"Call to undefined method Rubix\\ML\\Datasets\\Unlabeled::numFeatures()","Code":0,"Trace":[{"file":"/var/www/html/custom_apps/mail/lib/Service/Classification/FeatureExtraction/CompositeExtractor.php","line":53,"function":"extract","class":"OCA\\Mail\\Service\\Classification\\FeatureExtraction\\SubjectExtractor","type":"->","args":["*** sensitive parameters replaced ***"]},{"function":"OCA\\Mail\\Service\\Classification\\FeatureExtraction\\{closure}","class":"OCA\\Mail\\Service\\Classification\\FeatureExtraction\\CompositeExtractor","type":"::","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/custom_apps/mail/lib/functions.php","line":19,"function":"array_map","args":[["Closure"],[["OCA\\Mail\\Service\\Classification\\FeatureExtraction\\ImportantMessagesExtractor"],["OCA\\Mail\\Service\\Classification\\FeatureExtraction\\ReadMessagesExtractor"],["OCA\\Mail\\Service\\Classification\\FeatureExtraction\\RepliedMessagesExtractor"],["OCA\\Mail\\Service\\Classification\\FeatureExtraction\\SentMessagesExtractor"],"*** sensitive parameters replaced ***"]]},{"file":"/var/www/html/custom_apps/mail/lib/Service/Classification/FeatureExtraction/CompositeExtractor.php","line":52,"function":"OCA\\Mail\\array_flat_map","args":[["Closure"],[["OCA\\Mail\\Service\\Classification\\FeatureExtraction\\ImportantMessagesExtractor"],["OCA\\Mail\\Service\\Classification\\FeatureExtraction\\ReadMessagesExtractor"],["OCA\\Mail\\Service\\Classification\\FeatureExtraction\\RepliedMessagesExtractor"],["OCA\\Mail\\Service\\Classification\\FeatureExtraction\\SentMessagesExtractor"],"*** sensitive parameters replaced ***"]]},{"file":"/var/www/html/custom_apps/mail/lib/Service/Classification/ImportanceClassifier.php","line":408,"function":"extract","class":"OCA\\Mail\\Service\\Classification\\FeatureExtraction\\CompositeExtractor","type":"->","args":["*** sensitive parameters replaced ***"]},{"function":"OCA\\Mail\\Service\\Classification\\{closure}","class":"OCA\\Mail\\Service\\Classification\\ImportanceClassifier","type":"::","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/custom_apps/mail/lib/Service/Classification/ImportanceClassifier.php","line":402,"function":"array_map","args":[["Closure"],["*** sensitive parameters replaced ***",["OCA\\Mail\\Db\\Message",9031],["OCA\\Mail\\Db\\Message",9028],["OCA\\Mail\\Db\\Message",9027],["OCA\\Mail\\Db\\Message",9025],"And 164 more entries, set log level to debug to see all entries"]]},{"file":"/var/www/html/custom_apps/mail/lib/Service/Classification/ImportanceClassifier.php","line":193,"function":"getFeaturesAndImportance","class":"OCA\\Mail\\Service\\Classification\\ImportanceClassifier","type":"->","args":["*** sensitive parameters replaced ***",["*** sensitive parameters replaced ***",["OCA\\Mail\\Db\\Mailbox",11],["OCA\\Mail\\Db\\Mailbox",12],["OCA\\Mail\\Db\\Mailbox",14],["OCA\\Mail\\Db\\Mailbox",15],"And 5 more entries, set log level to debug to see all entries"],[["OCA\\Mail\\Db\\Mailbox",8]],["*** sensitive parameters replaced ***",["OCA\\Mail\\Db\\Message",9031],["OCA\\Mail\\Db\\Message",9028],["OCA\\Mail\\Db\\Message",9027],["OCA\\Mail\\Db\\Message",9025],"And 164 more entries, set log level to debug to see all entries"],["OCA\\Mail\\Service\\Classification\\FeatureExtraction\\CompositeExtractor"]]},{"file":"/var/www/html/custom_apps/mail/lib/Service/Classification/ImportanceClassifier.php","line":234,"function":"buildDataSet","class":"OCA\\Mail\\Service\\Classification\\ImportanceClassifier","type":"->","args":["*** sensitive parameters replaced ***",["OCA\\Mail\\Service\\Classification\\FeatureExtraction\\CompositeExtractor"],"*** sensitive parameters replaced ***",["OCA\\Mail\\Support\\PerformanceLoggerTask"],"*** sensitive parameters replaced ***"]},{"file":"/var/www/html/custom_apps/mail/lib/Service/Classification/ImportanceClassifier.php","line":442,"function":"train","class":"OCA\\Mail\\Service\\Classification\\ImportanceClassifier","type":"->","args":["*** sensitive parameters replaced ***","*** sensitive parameters replaced ***"]},{"file":"/var/www/html/custom_apps/mail/lib/Service/Classification/NewMessagesClassifier.php","line":85,"function":"classifyImportance","class":"OCA\\Mail\\Service\\Classification\\ImportanceClassifier","type":"->","args":["*** sensitive parameters replaced ***",["*** sensitive parameters replaced ***"],"*** sensitive parameters replaced ***"]},{"file":"/var/www/html/custom_apps/mail/lib/Service/Sync/ImapToDbSynchronizer.php","line":445,"function":"classifyNewMessages","class":"OCA\\Mail\\Service\\Classification\\NewMessagesClassifier","type":"->","args":[["*** sensitive parameters replaced ***"],"*** sensitive parameters replaced ***","*** sensitive parameters replaced ***",["OCA\\Mail\\Db\\Tag",6]]},{"file":"/var/www/html/custom_apps/mail/lib/Service/Sync/ImapToDbSynchronizer.php","line":263,"function":"runPartialSync","class":"OCA\\Mail\\Service\\Sync\\ImapToDbSynchronizer","type":"->","args":["*** sensitive parameters replaced ***","*** sensitive parameters replaced ***","*** sensitive parameters replaced ***","*** sensitive parameters replaced ***","*** sensitive parameters replaced ***","*** sensitive parameters replaced ***","*** sensitive parameters replaced ***"]},{"file":"/var/www/html/custom_apps/mail/lib/Service/Sync/ImapToDbSynchronizer.php","line":133,"function":"sync","class":"OCA\\Mail\\Service\\Sync\\ImapToDbSynchronizer","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/custom_apps/mail/lib/BackgroundJob/SyncJob.php","line":93,"function":"syncAccount","class":"OCA\\Mail\\Service\\Sync\\ImapToDbSynchronizer","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/lib/public/BackgroundJob/Job.php","line":61,"function":"run","class":"OCA\\Mail\\BackgroundJob\\SyncJob","type":"->","args":[[2]]},{"file":"/var/www/html/lib/public/BackgroundJob/TimedJob.php","line":83,"function":"start","class":"OCP\\BackgroundJob\\Job","type":"->","args":[["OC\\BackgroundJob\\JobList"]]},{"file":"/var/www/html/lib/public/BackgroundJob/TimedJob.php","line":73,"function":"start","class":"OCP\\BackgroundJob\\TimedJob","type":"->","args":[["OC\\BackgroundJob\\JobList"]]},{"file":"/var/www/html/cron.php","line":162,"function":"execute","class":"OCP\\BackgroundJob\\TimedJob","type":"->","args":[["OC\\BackgroundJob\\JobList"]]}],"File":"/var/www/html/custom_apps/mail/lib/Service/Classification/FeatureExtraction/SubjectExtractor.php","Line":89},"message":"Cron mail sync failed for account {accountId}","exception":[],"CustomMessage":"Cron mail sync failed for account 2"},"id":"67ff8eaa799eb"}

[st3iny]

We already track the undefined method error here: #10645

It does not seem to be related to the sync issue. Otherwise, more people would have reported similar issues.

You could look if there is an IMAP log file in your data directory to get some more information. It should have the following name: horde_imap.log

[ChristophWurst]

And before you lose any more data, @Betzejoe, make sure you back up your emails.

emails get deleted by synchronizing

What indicates that Nextcloud Mail is deleting? Do you have any other applications connected to that IMAP account?

[Betzejoe]

I disabled the mail app since this time I got no further mails lost.
Yes I have my mobile devices connected to the IMAP account. But there was no change. The only thing I changed was updating the Mail-app in nextcloud and since it is disabled no mails are deleted.
I tried to find any log related to imap within my docker container and also on the server. I can´t find it.
Does Mail app not write any protocol when synchronizing emails?

In nextcloud log I found following errors which seem to be also related to email sync:
[core] Fehler: Error while running background job OCA\Mail\BackgroundJob\RepairSyncJob (id: 28758, arguments: {"accountId":1})
von ? von -- um 15.04.2025, 07:35:04

{"reqId":"BUKvQcMHDxo5Sod7sNT4","level":3,"time":"2025-04-15T05:35:04+00:00","remoteAddr":"","user":"--","app":"core","method":"","url":"--","message":"Error while running background job OCA\Mail\BackgroundJob\RepairSyncJob (id: 28758, arguments: {"accountId":1})","userAgent":"--","version":"30.0.0.14","exception":{"Exception":"OCA\Mail\Exception\MailboxLockedException","Message":"6 is already being synced","Code":0,"Trace":[{"file":"/var/www/html/custom_apps/mail/lib/Db/MailboxMapper.php","line":169,"function":"from","class":"OCA\Mail\Exception\MailboxLockedException","type":"::","args":[["OCA\Mail\Db\Mailbox",6]]},{"file":"/var/www/html/custom_apps/mail/lib/Db/MailboxMapper.php","line":211,"function":"lockForSync","class":"OCA\Mail\Db\MailboxMapper","type":"->","args":[["OCA\Mail\Db\Mailbox",6],"sync_vanished_lock",1744695303]},{"file":"/var/www/html/custom_apps/mail/lib/Service/Sync/ImapToDbSynchronizer.php","line":542,"function":"lockForVanishedSync","class":"OCA\Mail\Db\MailboxMapper","type":"->","args":[["OCA\Mail\Db\Mailbox",6]]},{"file":"/var/www/html/custom_apps/mail/lib/Service/Sync/SyncService.php","line":95,"function":"repairSync","class":"OCA\Mail\Service\Sync\ImapToDbSynchronizer","type":"->","args":[["OCA\Mail\Account"],["OCA\Mail\Db\Mailbox",6],["OC\AppFramework\ScopedPsrLogger"]]},{"file":"/var/www/html/custom_apps/mail/lib/BackgroundJob/RepairSyncJob.php","line":83,"function":"repairSync","class":"OCA\Mail\Service\Sync\SyncService","type":"->","args":[["OCA\Mail\Account"],["OCA\Mail\Db\Mailbox",6]]},{"file":"/var/www/html/lib/public/BackgroundJob/Job.php","line":61,"function":"run","class":"OCA\Mail\BackgroundJob\RepairSyncJob","type":"->","args":[[1]]},{"file":"/var/www/html/lib/public/BackgroundJob/TimedJob.php","line":83,"function":"start","class":"OCP\BackgroundJob\Job","type":"->","args":[["OC\BackgroundJob\JobList"]]},{"file":"/var/www/html/lib/public/BackgroundJob/TimedJob.php","line":73,"function":"start","class":"OCP\BackgroundJob\TimedJob","type":"->","args":[["OC\BackgroundJob\JobList"]]},{"file":"/var/www/html/cron.php","line":162,"function":"execute","class":"OCP\BackgroundJob\TimedJob","type":"->","args":[["OC\BackgroundJob\JobList"]]}],"File":"/var/www/html/custom_apps/mail/lib/Exception/MailboxLockedException.php","Line":17,"message":"Error while running background job OCA\Mail\BackgroundJob\RepairSyncJob (id: 28758, arguments: {"accountId":1})","exception":[],"CustomMessage":"Error while running background job OCA\Mail\BackgroundJob\RepairSyncJob (id: 28758, arguments: {"accountId":1})"},"id":"6800084e4b0c3"}

[core] Fehler: Error while running background job OCA\Mail\BackgroundJob\RepairSyncJob (id: 28759, arguments: {"accountId":2})
von ? von -- um 10.04.2025, 03:20:32

{"reqId":"XYgl1dnKbQCHVrOTyg1r","level":3,"time":"2025-04-10T01:20:32+00:00","remoteAddr":"","user":"--","app":"core","method":"","url":"--","message":"Error while running background job OCA\Mail\BackgroundJob\RepairSyncJob (id: 28759, arguments: {"accountId":2})","userAgent":"--","version":"30.0.0.14","exception":{"Exception":"OCA\Mail\Exception\ServiceException","Message":"Repair sync failed for 2:Posteingang: Error connecting to mail server.","Code":0,"Trace":[{"file":"/var/www/html/custom_apps/mail/lib/Service/Sync/SyncService.php","line":95,"function":"repairSync","class":"OCA\Mail\Service\Sync\ImapToDbSynchronizer","type":"->","args":[["OCA\Mail\Account"],["OCA\Mail\Db\Mailbox",12],["OC\AppFramework\ScopedPsrLogger"]]},{"file":"/var/www/html/custom_apps/mail/lib/BackgroundJob/RepairSyncJob.php","line":83,"function":"repairSync","class":"OCA\Mail\Service\Sync\SyncService","type":"->","args":[["OCA\Mail\Account"],["OCA\Mail\Db\Mailbox",12]]},{"file":"/var/www/html/lib/public/BackgroundJob/Job.php","line":61,"function":"run","class":"OCA\Mail\BackgroundJob\RepairSyncJob","type":"->","args":[[2]]},{"file":"/var/www/html/lib/public/BackgroundJob/TimedJob.php","line":83,"function":"start","class":"OCP\BackgroundJob\Job","type":"->","args":[["OC\BackgroundJob\JobList"]]},{"file":"/var/www/html/lib/public/BackgroundJob/TimedJob.php","line":73,"function":"start","class":"OCP\BackgroundJob\TimedJob","type":"->","args":[["OC\BackgroundJob\JobList"]]},{"file":"/var/www/html/cron.php","line":162,"function":"execute","class":"OCP\BackgroundJob\TimedJob","type":"->","args":[["OC\BackgroundJob\JobList"]]}],"File":"/var/www/html/custom_apps/mail/lib/Service/Sync/ImapToDbSynchronizer.php","Line":567,"Previous":{"Exception":"Horde_Imap_Client_Exception","Message":"Error connecting to mail server.","Code":11,"Trace":[{"file":"/var/www/html/custom_apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Socket.php","line":375,"function":"_connect","class":"Horde_Imap_Client_Socket","type":"->","args":[]},{"file":"/var/www/html/custom_apps/mail/lib/IMAP/HordeImapClient.php","line":59,"function":"_login","class":"Horde_Imap_Client_Socket","type":"->","args":["*** sensitive parameters replaced "]},{"file":"/var/www/html/custom_apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php","line":853,"function":"_login","class":"OCA\Mail\IMAP\HordeImapClient","type":"->","args":[" sensitive parameters replaced "]},{"file":"/var/www/html/custom_apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Base.php","line":2810,"function":"login","class":"Horde_Imap_Client_Base","type":"->","args":[" sensitive parameters replaced ***"]},{"file":"/var/www/html/custom_apps/mail/lib/Service/Sync/ImapToDbSynchronizer.php","line":554,"function":"vanished","class":"Horde_Imap_Client_Base","type":"->","args":[["Horde_Imap_Client_Mailbox"],0,[["Horde_Imap_Client_Ids",false]]]},{"file":"/var/www/html/custom_apps/mail/lib/Service/Sync/SyncService.php","line":95,"function":"repairSync","class":"OCA\Mail\Service\Sync\ImapToDbSynchronizer","type":"->","args":[["OCA\Mail\Account"],["OCA\Mail\Db\Mailbox",12],["OC\AppFramework\ScopedPsrLogger"]]},{"file":"/var/www/html/custom_apps/mail/lib/BackgroundJob/RepairSyncJob.php","line":83,"function":"repairSync","class":"OCA\Mail\Service\Sync\SyncService","type":"->","args":[["OCA\Mail\Account"],["OCA\Mail\Db\Mailbox",12]]},{"file":"/var/www/html/lib/public/BackgroundJob/Job.php","line":61,"function":"run","class":"OCA\Mail\BackgroundJob\RepairSyncJob","type":"->","args":[[2]]},{"file":"/var/www/html/lib/public/BackgroundJob/TimedJob.php","line":83,"function":"start","class":"OCP\BackgroundJob\Job","type":"->","args":[["OC\BackgroundJob\JobList"]]},{"file":"/var/www/html/lib/public/BackgroundJob/TimedJob.php","line":73,"function":"start","class":"OCP\BackgroundJob\TimedJob","type":"->","args":[["OC\BackgroundJob\JobList"]]},{"file":"/var/www/html/cron.php","line":162,"function":"execute","class":"OCP\BackgroundJob\TimedJob","type":"->","args":[["OC\BackgroundJob\JobList"]]}],"File":"/var/www/html/custom_apps/mail/vendor/bytestream/horde-imap-client/lib/Horde/Imap/Client/Socket.php","Line":607},"message":"Error while running background job OCA\Mail\BackgroundJob\RepairSyncJob (id: 28759, arguments: {"accountId":2})","exception":[],"CustomMessage":"Error while running background job OCA\Mail\BackgroundJob\RepairSyncJob (id: 28759, arguments: {"accountId":2})"},"id":"6800089272c6a"}

[core] Fehler: Error while running background job OCA\Mail\BackgroundJob\RepairSyncJob (id: 28758, arguments: {"accountId":1})
von ? von -- um 10.04.2025, 03:15:02

{"reqId":"MryL7S9UJjLPz7O5ld3Q","level":3,"time":"2025-04-10T01:15:02+00:00","remoteAddr":"","user":"--","app":"core","method":"","url":"--","message":"Error while running background job OCA\Mail\BackgroundJob\RepairSyncJob (id: 28758, arguments: {"accountId":1})","userAgent":"--","version":"30.0.0.14","exception":{"Exception":"OCA\Mail\Exception\MailboxLockedException","Message":"6 is already being synced","Code":0,"Trace":[{"file":"/var/www/html/custom_apps/mail/lib/Db/MailboxMapper.php","line":169,"function":"from","class":"OCA\Mail\Exception\MailboxLockedException","type":"::","args":[["OCA\Mail\Db\Mailbox",6]]},{"file":"/var/www/html/custom_apps/mail/lib/Db/MailboxMapper.php","line":211,"function":"lockForSync","class":"OCA\Mail\Db\MailboxMapper","type":"->","args":[["OCA\Mail\Db\Mailbox",6],"sync_vanished_lock",1744247702]},{"file":"/var/www/html/custom_apps/mail/lib/Service/Sync/ImapToDbSynchronizer.php","line":542,"function":"lockForVanishedSync","class":"OCA\Mail\Db\MailboxMapper","type":"->","args":[["OCA\Mail\Db\Mailbox",6]]},{"file":"/var/www/html/custom_apps/mail/lib/Service/Sync/SyncService.php","line":95,"function":"repairSync","class":"OCA\Mail\Service\Sync\ImapToDbSynchronizer","type":"->","args":[["OCA\Mail\Account"],["OCA\Mail\Db\Mailbox",6],["OC\AppFramework\ScopedPsrLogger"]]},{"file":"/var/www/html/custom_apps/mail/lib/BackgroundJob/RepairSyncJob.php","line":83,"function":"repairSync","class":"OCA\Mail\Service\Sync\SyncService","type":"->","args":[["OCA\Mail\Account"],["OCA\Mail\Db\Mailbox",6]]},{"file":"/var/www/html/lib/public/BackgroundJob/Job.php","line":61,"function":"run","class":"OCA\Mail\BackgroundJob\RepairSyncJob","type":"->","args":[[1]]},{"file":"/var/www/html/lib/public/BackgroundJob/TimedJob.php","line":83,"function":"start","class":"OCP\BackgroundJob\Job","type":"->","args":[["OC\BackgroundJob\JobList"]]},{"file":"/var/www/html/lib/public/BackgroundJob/TimedJob.php","line":73,"function":"start","class":"OCP\BackgroundJob\TimedJob","type":"->","args":[["OC\BackgroundJob\JobList"]]},{"file":"/var/www/html/cron.php","line":162,"function":"execute","class":"OCP\BackgroundJob\TimedJob","type":"->","args":[["OC\BackgroundJob\JobList"]]}],"File":"/var/www/html/custom_apps/mail/lib/Exception/MailboxLockedException.php","Line":17,"message":"Error while running background job OCA\Mail\BackgroundJob\RepairSyncJob (id: 28758, arguments: {"accountId":1})","exception":[],"CustomMessage":"Error while running background job OCA\Mail\BackgroundJob\RepairSyncJob (id: 28758, arguments: {"accountId":1})"},"id":"6800089272c82"}

[ChristophWurst]

The previous synchronization failed and left the mailbox locked. That is why other sync operations can't lock the already locked mailbox. This will go away over time.

After you have backed up your emails, you could enable debug mode in Nextcloud https://docs.nextcloud.com/server/latest/developer_manual/digging_deeper/debugging.html#debug-mode
This will ensure that any further IMAP communication is written to a logfile.

[ChristophWurst]

@Betzejoe did you enable automatic trash deletion?

[Betzejoe]

No. I did not enable this. Still I´m searching for the reason. Also at my other devices nothing was chnaged to delete emails.
I also checked the settings for the folder in web.de like described in the help of web.de. But the deletions policy for inbox is set to "never". I also checked all automatic filters. No filters or automatic actions active.