[Bug]: Mail: Re mails content not shown

[lmarquar]

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github OR Nextcloud Community Forum (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

As you see the Email does not get displayed, only the history shows.

Steps to reproduce

1. Respond to any email
2. Receive an answer to your response
3. open the answer

Expected behavior

the Email selected should be readable

Nextcloud Server version

32

Operating system

Debian/Ubuntu

PHP engine version

None

Web server

Apache (supported)

Database engine version

PostgreSQL

Is this bug present after an update or on a fresh install?

Upgraded to a MAJOR version (ex. 31 to 32)

Are you using the Nextcloud Server Encryption module?

None

What user-backends are you using?

• Default user-backend (database)
• LDAP/ Active Directory
• SSO - SAML
• Other

Configuration report

{
    "system": {
        "one-click-instance": true,
        "one-click-instance.user-limit": 100,
        "memcache.local": "\\OC\\Memcache\\APCu",
        "apps_paths": [
            {
                "path": "\/var\/www\/html\/apps",
                "url": "\/apps",
                "writable": false
            },
            {
                "path": "\/var\/www\/html\/custom_apps",
                "url": "\/custom_apps",
                "writable": true
            }
        ],
        "appsallowlist": false,
        "check_data_directory_permissions": false,
        "memcache.distributed": "\\OC\\Memcache\\Redis",
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "password": "***REMOVED SENSITIVE VALUE***",
            "port": 6379
        },
        "overwritehost": "cloud.aiomvp.com",
        "overwriteprotocol": "https",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "localhost",
            "cloud.aiomvp.com"
        ],
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "dbtype": "pgsql",
        "version": "32.0.6.1",
        "overwrite.cli.url": "https:\/\/cloud.aiomvp.com\/",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "oc_",
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "maintenance": false,
        "loglevel": 2,
        "log_type": "file",
        "logfile": "\/var\/www\/html\/data\/nextcloud.log",
        "log_rotate_size": 10485760,
        "log.condition": {
            "apps": [
                "admin_audit"
            ]
        },
        "preview_max_x": 2048,
        "preview_max_y": 2048,
        "jpeg_quality": 60,
        "enabledPreviewProviders": {
            "1": "OC\\Preview\\Image",
            "2": "OC\\Preview\\MarkDown",
            "3": "OC\\Preview\\MP3",
            "4": "OC\\Preview\\TXT",
            "5": "OC\\Preview\\OpenDocument",
            "6": "OC\\Preview\\Movie",
            "7": "OC\\Preview\\Krita"
        },
        "enable_previews": true,
        "upgrade.disable-web": true,
        "mail_smtpmode": "smtp",
        "trashbin_retention_obligation": "auto, 30",
        "versions_retention_obligation": "auto, 30",
        "activity_expire_days": 30,
        "simpleSignUpLink.shown": false,
        "share_folder": "\/Shared",
        "one-click-instance.link": "https:\/\/nextcloud.com\/all-in-one\/",
        "upgrade.cli-upgrade-link": "https:\/\/github.com\/nextcloud\/all-in-one\/discussions\/2726",
        "updatedirectory": "\/nc-updater",
        "maintenance_window_start": 100,
        "allow_local_remote_servers": true,
        "davstorage.request_timeout": 3600,
        "htaccess.RewriteBase": "\/",
        "dbpersistent": false,
        "auth.bruteforce.protection.enabled": true,
        "ratelimit.protection.enabled": true,
        "files_external_allow_create_new_local": true,
        "trusted_proxies": "***REMOVED SENSITIVE VALUE***",
        "preview_imaginary_key": "***REMOVED SENSITIVE VALUE***",
        "default_phone_region": "DE\n",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_sendmailmode": "smtp",
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpsecure": "ssl",
        "mail_smtpauth": 1,
        "mail_smtpname": "***REMOVED SENSITIVE VALUE***",
        "mail_smtppassword": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpport": "465 \/ 587",
        "data-fingerprint": "3c9c3413f9ad129f7e3dfb9a7f7772d7",
        "documentation_url.server_logs": "https:\/\/github.com\/nextcloud\/all-in-one\/discussions\/5425",
        "updatechecker": false,
        "updater.release.channel": "stable",
        "DOMAIN": "cloud.aiomvp.com",
        "AIO_VERSION": "v12.8.0"
    }
}

List of activated Apps

Enabled:
  - activity: 5.0.0
  - admin_audit: 1.22.0
  - appointments: 2.6.3
  - assistant: 2.13.0
  - bruteforcesettings: 5.0.0
  - calendar: 6.2.1
  - circles: 32.0.0
  - cloud_federation_api: 1.16.0
  - comments: 1.22.0
  - contacts: 8.3.4
  - contactsinteraction: 1.13.1
  - dashboard: 7.12.0
  - dav: 1.34.2
  - deck: 1.16.3
  - federatedfilesharing: 1.22.0
  - federation: 1.22.0
  - files: 2.4.0
  - files_downloadlimit: 5.0.0-dev.0
  - files_external: 1.24.1
  - files_pdfviewer: 5.0.0
  - files_reminders: 1.5.0
  - files_sharing: 1.24.1
  - files_trashbin: 1.22.0
  - files_versions: 1.25.0
  - firstrunwizard: 5.0.0
  - forms: 5.2.4
  - integration_openproject: 2.11.1
  - logreader: 5.0.0
  - lookup_server_connector: 1.20.0
  - mail: 5.7.1
  - nextcloud-aio: 0.8.0
  - nextcloud_announcements: 4.0.0
  - notes: 4.13.0
  - notifications: 5.0.0
  - notify_push: 1.3.1
  - oauth2: 1.20.0
  - password_policy: 4.0.0
  - passwords: 2026.2.20
  - photos: 5.0.0
  - privacy: 4.0.0
  - profile: 1.1.0
  - provisioning_api: 1.22.0
  - recommendations: 5.0.0
  - related_resources: 3.0.0
  - richdocuments: 9.0.3
  - serverinfo: 4.0.0
  - settings: 1.15.1
  - sharebymail: 1.22.0
  - support: 4.0.0
  - survey_client: 4.0.0
  - systemtags: 1.22.0
  - tasks: 0.17.1
  - text: 6.0.1
  - theming: 2.7.0
  - twofactor_backupcodes: 1.21.0
  - twofactor_totp: 14.0.0
  - updatenotification: 1.22.0
  - user_status: 1.12.0
  - viewer: 5.0.0
  - weather_status: 1.12.0
  - webhook_listeners: 1.3.0
  - whiteboard: 1.5.7
  - workflowengine: 2.14.0
Disabled:
  - app_api: 32.0.0 (installed 32.0.0)
  - encryption: 2.20.0
  - integration_openai: 3.10.1 (installed 3.10.1)
  - multiboards: 1.0.4 (installed 1.0.4)
  - richdocumentscode: 25.4.902 (installed 25.4.902)
  - suspicious_login: 10.0.0
  - twofactor_nextcloud_notification: 6.0.0
  - user_ldap: 1.23.0

Nextcloud Signing status

No errors have been found.

Nextcloud Logs

{"reqId":"PB2gH39aa7hTFy3zPZ9t","level":3,"time":"2026-04-24T20:01:42+00:00","remoteAddr":"","user":"--","app":"mail","method":"","url":"--","scriptName":"/var/www/html/cron.php","message":"Cron mail sync failed for account 9","userAgent":"--","version":"32.0.6.1","occ_command":["/var/www/html/cron.php"],"exception":{"Exception":"OCA\\Mail\\Exception\\MailboxLockedException","Message":"50 is already being synced","Code":0,"Trace":[{"file":"/var/www/html/custom_apps/mail/lib/Db/MailboxMapper.php","line":182,"function":"from","class":"OCA\\Mail\\Exception\\MailboxLockedException","type":"::","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/custom_apps/mail/lib/Db/MailboxMapper.php","line":193,"function":"lockForSync","class":"OCA\\Mail\\Db\\MailboxMapper","type":"->","args":["*** sensitive parameters replaced ***","sync_new_lock","*** sensitive parameters replaced ***"]},{"file":"/var/www/html/custom_apps/mail/lib/Service/Sync/ImapToDbSynchronizer.php","line":243,"function":"lockForNewSync","class":"OCA\\Mail\\Db\\MailboxMapper","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/custom_apps/mail/lib/Service/Sync/ImapToDbSynchronizer.php","line":134,"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":128,"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":[{"accountId":9}]},{"file":"/var/www/html/lib/public/BackgroundJob/TimedJob.php","line":97,"function":"start","class":"OCP\\BackgroundJob\\Job","type":"->","args":[{"__class__":"OC\\BackgroundJob\\JobList"}]},{"file":"/var/www/html/lib/public/BackgroundJob/TimedJob.php","line":84,"function":"start","class":"OCP\\BackgroundJob\\TimedJob","type":"->","args":[{"__class__":"OC\\BackgroundJob\\JobList"}]},{"file":"/var/www/html/cron.php","line":175,"function":"execute","class":"OCP\\BackgroundJob\\TimedJob","type":"->","args":[{"__class__":"OC\\BackgroundJob\\JobList"}]}],"File":"/var/www/html/custom_apps/mail/lib/Exception/MailboxLockedException.php","Line":17,"message":"Cron mail sync failed for account {accountId}","exception":[],"CustomMessage":"Cron mail sync failed for account 9"},"id":"69ec7d99ba871"}

Additional info

well i think this might be a general problem. Does anyone have the same issues with the Mail-service?

[kesselb]

Hey,

mail: 5.7.1

I would recommend to start with updating the mail app ;)

[tflatka]

Hi,
yes we have multiple issues with displaying mail messages, especially when they come from China with some strange encoding or mainly messages coming from Outlook.com.
Is there any email I can forward the Source code to, I do not want to publish the mails here in the public forum?

Cheers
Thorsten

[kesselb]

@tflatka you can forward them as eml to danielk@nextcloud.com. Likely another case of #11363.