ERROR: invalid byte sequence for encoding \"UTF8\"

Steps to reproduce

I have a specific folder in my mailbox that is full of mostly French emails, and presumably Mail isn't liking something in there.
When I click on that folder, the browser just loads endlessly and sometimes blink, when it seems to retry the request.

Sadly I can't tell you what exactly.

Expected behavior

The folder should load.

Actual behavior

The browser shows the loading circle, and blink every few seconds when it retries.
On every retry, the following is logged :

{"reqId":"rFNnaKRFIpiJDpHX08or","level":3,"time":"2023-01-20T09:24:46+00:00","remoteAddr":"172.21.9.209","user":"myuser","app":"mail","method":"POST","url":"/apps/mail/api/mailboxes/4/sync","message":"Sync failed for 1:myfolder: An exception occurred while executing a query: SQLSTATE[22021]: Character not in repertoire: 7 ERROR:  invalid byte sequence for encoding \"UTF8\": 0xc1 0xbe","userAgent":"Mozilla/5.0 (X11; Linux x86_64; rv:108.0) Gecko/20100101 Firefox/108.0","version":"25.0.3.2","exception":{"Exception":"OCA\\Mail\\Exception\\ServiceException","Message":"Sync failed for 1:myfolder: An exception occurred while executing a query: SQLSTATE[22021]: Character not in repertoire: 7 ERROR:  invalid byte sequence for encoding \"UTF8\": 0xc1 0xbe","Code":0,"Trace":[{"file":"/config/www/nextcloud/apps/mail/lib/Service/Sync/SyncService.php","line":126,"function":"sync","class":"OCA\\Mail\\Service\\Sync\\ImapToDbSynchronizer","type":"->"},{"file":"/config/www/nextcloud/apps/mail/lib/Controller/MailboxesController.php","line":153,"function":"syncMailbox","class":"OCA\\Mail\\Service\\Sync\\SyncService","type":"->"},{"file":"/config/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","line":225,"function":"sync","class":"OCA\\Mail\\Controller\\MailboxesController","type":"->"},{"file":"/config/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","line":133,"function":"executeController","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/config/www/nextcloud/lib/private/AppFramework/App.php","line":172,"function":"dispatch","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/config/www/nextcloud/lib/private/Route/Router.php","line":298,"function":"main","class":"OC\\AppFramework\\App","type":"::"},{"file":"/config/www/nextcloud/lib/base.php","line":1047,"function":"match","class":"OC\\Route\\Router","type":"->"},{"file":"/config/www/nextcloud/index.php","line":36,"function":"handleRequest","class":"OC","type":"::"}],"File":"/config/www/nextcloud/apps/mail/lib/Service/Sync/ImapToDbSynchronizer.php","Line":254,"Previous":{"Exception":"Doctrine\\DBAL\\Exception\\DriverException","Message":"An exception occurred while executing a query: SQLSTATE[22021]: Character not in repertoire: 7 ERROR:  invalid byte sequence for encoding \"UTF8\": 0xc1 0xbe","Code":7,"Trace":[{"file":"/config/www/nextcloud/3rdparty/doctrine/dbal/src/Connection.php","line":1780,"function":"convert","class":"Doctrine\\DBAL\\Driver\\API\\PostgreSQL\\ExceptionConverter","type":"->"},{"file":"/config/www/nextcloud/3rdparty/doctrine/dbal/src/Connection.php","line":1719,"function":"handleDriverException","class":"Doctrine\\DBAL\\Connection","type":"->"},{"file":"/config/www/nextcloud/3rdparty/doctrine/dbal/src/Connection.php","line":1173,"function":"convertExceptionDuringQuery","class":"Doctrine\\DBAL\\Connection","type":"->"},{"file":"/config/www/nextcloud/lib/private/DB/Connection.php","line":294,"function":"executeStatement","class":"Doctrine\\DBAL\\Connection","type":"->"},{"file":"/config/www/nextcloud/3rdparty/doctrine/dbal/src/Query/QueryBuilder.php","line":354,"function":"executeStatement","class":"OC\\DB\\Connection","type":"->"},{"file":"/config/www/nextcloud/lib/private/DB/QueryBuilder/QueryBuilder.php","line":281,"function":"execute","class":"Doctrine\\DBAL\\Query\\QueryBuilder","type":"->"},{"file":"/config/www/nextcloud/apps/mail/lib/Db/MessageMapper.php","line":340,"function":"execute","class":"OC\\DB\\QueryBuilder\\QueryBuilder","type":"->"},{"file":"/config/www/nextcloud/apps/mail/lib/Service/Sync/ImapToDbSynchronizer.php","line":316,"function":"insertBulk","class":"OCA\\Mail\\Db\\MessageMapper","type":"->"},{"file":"/config/www/nextcloud/apps/mail/lib/Service/Sync/ImapToDbSynchronizer.php","line":230,"function":"runInitialSync","class":"OCA\\Mail\\Service\\Sync\\ImapToDbSynchronizer","type":"->"},{"file":"/config/www/nextcloud/apps/mail/lib/Service/Sync/SyncService.php","line":126,"function":"sync","class":"OCA\\Mail\\Service\\Sync\\ImapToDbSynchronizer","type":"->"},{"file":"/config/www/nextcloud/apps/mail/lib/Controller/MailboxesController.php","line":153,"function":"syncMailbox","class":"OCA\\Mail\\Service\\Sync\\SyncService","type":"->"},{"file":"/config/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","line":225,"function":"sync","class":"OCA\\Mail\\Controller\\MailboxesController","type":"->"},{"file":"/config/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","line":133,"function":"executeController","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/config/www/nextcloud/lib/private/AppFramework/App.php","line":172,"function":"dispatch","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/config/www/nextcloud/lib/private/Route/Router.php","line":298,"function":"main","class":"OC\\AppFramework\\App","type":"::"},{"file":"/config/www/nextcloud/lib/base.php","line":1047,"function":"match","class":"OC\\Route\\Router","type":"->"},{"file":"/config/www/nextcloud/index.php","line":36,"function":"handleRequest","class":"OC","type":"::"}],"File":"/config/www/nextcloud/3rdparty/doctrine/dbal/src/Driver/API/PostgreSQL/ExceptionConverter.php","Line":83,"Previous":{"Exception":"Doctrine\\DBAL\\Driver\\PDO\\Exception","Message":"SQLSTATE[22021]: Character not in repertoire: 7 ERROR:  invalid byte sequence for encoding \"UTF8\": 0xc1 0xbe","Code":7,"Trace":[{"file":"/config/www/nextcloud/3rdparty/doctrine/dbal/src/Driver/PDO/Statement.php","line":94,"function":"new","class":"Doctrine\\DBAL\\Driver\\PDO\\Exception","type":"::"},{"file":"/config/www/nextcloud/3rdparty/doctrine/dbal/src/Connection.php","line":1163,"function":"execute","class":"Doctrine\\DBAL\\Driver\\PDO\\Statement","type":"->"},{"file":"/config/www/nextcloud/lib/private/DB/Connection.php","line":294,"function":"executeStatement","class":"Doctrine\\DBAL\\Connection","type":"->"},{"file":"/config/www/nextcloud/3rdparty/doctrine/dbal/src/Query/QueryBuilder.php","line":354,"function":"executeStatement","class":"OC\\DB\\Connection","type":"->"},{"file":"/config/www/nextcloud/lib/private/DB/QueryBuilder/QueryBuilder.php","line":281,"function":"execute","class":"Doctrine\\DBAL\\Query\\QueryBuilder","type":"->"},{"file":"/config/www/nextcloud/apps/mail/lib/Db/MessageMapper.php","line":340,"function":"execute","class":"OC\\DB\\QueryBuilder\\QueryBuilder","type":"->"},{"file":"/config/www/nextcloud/apps/mail/lib/Service/Sync/ImapToDbSynchronizer.php","line":316,"function":"insertBulk","class":"OCA\\Mail\\Db\\MessageMapper","type":"->"},{"file":"/config/www/nextcloud/apps/mail/lib/Service/Sync/ImapToDbSynchronizer.php","line":230,"function":"runInitialSync","class":"OCA\\Mail\\Service\\Sync\\ImapToDbSynchronizer","type":"->"},{"file":"/config/www/nextcloud/apps/mail/lib/Service/Sync/SyncService.php","line":126,"function":"sync","class":"OCA\\Mail\\Service\\Sync\\ImapToDbSynchronizer","type":"->"},{"file":"/config/www/nextcloud/apps/mail/lib/Controller/MailboxesController.php","line":153,"function":"syncMailbox","class":"OCA\\Mail\\Service\\Sync\\SyncService","type":"->"},{"file":"/config/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","line":225,"function":"sync","class":"OCA\\Mail\\Controller\\MailboxesController","type":"->"},{"file":"/config/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","line":133,"function":"executeController","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/config/www/nextcloud/lib/private/AppFramework/App.php","line":172,"function":"dispatch","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/config/www/nextcloud/lib/private/Route/Router.php","line":298,"function":"main","class":"OC\\AppFramework\\App","type":"::"},{"file":"/config/www/nextcloud/lib/base.php","line":1047,"function":"match","class":"OC\\Route\\Router","type":"->"},{"file":"/config/www/nextcloud/index.php","line":36,"function":"handleRequest","class":"OC","type":"::"}],"File":"/config/www/nextcloud/3rdparty/doctrine/dbal/src/Driver/PDO/Exception.php","Line":26,"Previous":{"Exception":"PDOException","Message":"SQLSTATE[22021]: Character not in repertoire: 7 ERROR:  invalid byte sequence for encoding \"UTF8\": 0xc1 0xbe","Code":"22021","Trace":[{"file":"/config/www/nextcloud/3rdparty/doctrine/dbal/src/Driver/PDO/Statement.php","line":92,"function":"execute","class":"PDOStatement","type":"->"},{"file":"/config/www/nextcloud/3rdparty/doctrine/dbal/src/Connection.php","line":1163,"function":"execute","class":"Doctrine\\DBAL\\Driver\\PDO\\Statement","type":"->"},{"file":"/config/www/nextcloud/lib/private/DB/Connection.php","line":294,"function":"executeStatement","class":"Doctrine\\DBAL\\Connection","type":"->"},{"file":"/config/www/nextcloud/3rdparty/doctrine/dbal/src/Query/QueryBuilder.php","line":354,"function":"executeStatement","class":"OC\\DB\\Connection","type":"->"},{"file":"/config/www/nextcloud/lib/private/DB/QueryBuilder/QueryBuilder.php","line":281,"function":"execute","class":"Doctrine\\DBAL\\Query\\QueryBuilder","type":"->"},{"file":"/config/www/nextcloud/apps/mail/lib/Db/MessageMapper.php","line":340,"function":"execute","class":"OC\\DB\\QueryBuilder\\QueryBuilder","type":"->"},{"file":"/config/www/nextcloud/apps/mail/lib/Service/Sync/ImapToDbSynchronizer.php","line":316,"function":"insertBulk","class":"OCA\\Mail\\Db\\MessageMapper","type":"->"},{"file":"/config/www/nextcloud/apps/mail/lib/Service/Sync/ImapToDbSynchronizer.php","line":230,"function":"runInitialSync","class":"OCA\\Mail\\Service\\Sync\\ImapToDbSynchronizer","type":"->"},{"file":"/config/www/nextcloud/apps/mail/lib/Service/Sync/SyncService.php","line":126,"function":"sync","class":"OCA\\Mail\\Service\\Sync\\ImapToDbSynchronizer","type":"->"},{"file":"/config/www/nextcloud/apps/mail/lib/Controller/MailboxesController.php","line":153,"function":"syncMailbox","class":"OCA\\Mail\\Service\\Sync\\SyncService","type":"->"},{"file":"/config/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","line":225,"function":"sync","class":"OCA\\Mail\\Controller\\MailboxesController","type":"->"},{"file":"/config/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","line":133,"function":"executeController","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/config/www/nextcloud/lib/private/AppFramework/App.php","line":172,"function":"dispatch","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/config/www/nextcloud/lib/private/Route/Router.php","line":298,"function":"main","class":"OC\\AppFramework\\App","type":"::"},{"file":"/config/www/nextcloud/lib/base.php","line":1047,"function":"match","class":"OC\\Route\\Router","type":"->"},{"file":"/config/www/nextcloud/index.php","line":36,"function":"handleRequest","class":"OC","type":"::"}],"File":"/config/www/nextcloud/3rdparty/doctrine/dbal/src/Driver/PDO/Statement.php","Line":92}}},"message":"Sync failed for 1:myfolder: An exception occurred while executing a query: SQLSTATE[22021]: Character not in repertoire: 7 ERROR:  invalid byte sequence for encoding \"UTF8\": 0xc1 0xbe","exception":{},"CustomMessage":"Sync failed for 1:myfolder: An exception occurred while executing a query: SQLSTATE[22021]: Character not in repertoire: 7 ERROR:  invalid byte sequence for encoding \"UTF8\": 0xc1 0xbe"}}

Mail app version

2.2.2

Mailserver or service

Gandi - should be pretty standard IMAP

Operating system

Docker linuxserver/nextcloud running on latest UnRAID

PHP engine version

PHP 8.0

Web server

Nginx

Database

PostgreSQL

Additional info

Might be the same as https://github.com/nextcloud/mail/issues/4320 but that's been closed with no solution or workaround, as far as I can tell.

My main inbox folder loads fine, this only happens in one specific folder I have.

Start with apps/mail/lib/Service/Sync/ImapToDbSynchronizer.php and apps/mail/lib/Db/MessageMapper.php, following the mailbox sync path shown in the trace. Reproduce the failure with a mailbox containing the problematic message and inspect how its data reaches PostgreSQL. Done means the folder sync completes without the invalid UTF8 error and the folder loads.