Today I upgraded a server at a customer.

I modified the config I had built over the last week, with the help of this list.

So far nearly everything works, but thunderbird complains about non-existing mailboxes like INBOX.

But we can access it, it's a bit strange.

In the filesystem it looks like:

ls -la /home/vmail/our.tld/user\@our.tld/

insgesamt 7096 drwx------ 69 vmail vmail 4096 2. Apr 19:00 . drwx------ 129 vmail vmail 12288 2. Apr 18:56 .. drwx------ 5 vmail vmail 4096 8. Jun 2021 .Administrator drwx------ 5 vmail vmail 4096 2. Apr 18:40 .Administrator.Archiv drwx------ 5 vmail vmail 4096 2. Apr 18:40 '.Administrator.Domainwechsel AquaCC' drwx------ 5 vmail vmail 4096 11. Mai 2025 .Archives drwx------ 5 vmail vmail 4096 2. Apr 18:40 .Archives.2001 drwx------ 5 vmail vmail 4096 2. Apr 18:40 .Archives.2002 drwx------ 5 vmail vmail 4096 2. Apr 18:40 .Archives.2003 drwx------ 5 vmail vmail 4096 12. Aug 2024 .Archives.2004 drwx------ 5 vmail vmail 4096 2. Apr 18:40 .Archives.2005 drwx------ 5 vmail vmail 4096 12. Aug 2024 .Archives.2006 drwx------ 5 vmail vmail 4096 12. Aug 2024 .Archives.2007 drwx------ 5 vmail vmail 4096 10. Feb 18:17 .Archives.2008 drwx------ 5 vmail vmail 4096 12. Aug 2024 .Archives.2009 drwx------ 5 vmail vmail 4096 12. Aug 2024 .Archives.2010 drwx------ 5 vmail vmail 4096 10. Feb 18:10 .Archives.2011 drwx------ 5 vmail vmail 4096 12. Aug 2024 .Archives.2012 drwx------ 5 vmail vmail 4096 12. Aug 2024 .Archives.2013 drwx------ 5 vmail vmail 4096 10. Feb 18:09 .Archives.2014 drwx------ 5 vmail vmail 4096 12. Aug 2024 .Archives.2015 drwx------ 5 vmail vmail 4096 2. Apr 17:51 .Archives.2016 drwx------ 5 vmail vmail 4096 11. Feb 11:57 .Archives.2017 drwx------ 5 vmail vmail 4096 10. Jun 2025 .Archives.2018 drwx------ 5 vmail vmail 4096 11. Feb 11:57 .Archives.2019 drwx------ 5 vmail vmail 4096 10. Feb 18:23 .Archives.2020 drwx------ 5 vmail vmail 4096 1. Apr 20:18 .Archives.2021 drwx------ 5 vmail vmail 4096 30. Mär 09:37 .Archives.2022 drwx------ 5 vmail vmail 4096 1. Apr 20:18 .Archives.2023 drwx------ 5 vmail vmail 4096 1. Apr 20:18 .Archives.2024 drwx------ 5 vmail vmail 4096 2. Apr 17:48 .Archives.2025 drwx------ 5 vmail vmail 4096 2. Apr 17:59 .Archives.2026 drwx------ 2 vmail vmail 323584 2. Apr 19:00 cur -rw------- 1 vmail vmail 0 2. Aug 2021 dovecot-acl-list -rw------- 1 vmail vmail 70712 2. Apr 18:37 dovecot.index -rw------- 1 vmail vmail 6266860 2. Apr 19:01 dovecot.index.cache -rw------- 1 vmail vmail 32160 2. Apr 19:00 dovecot.index.log -rw------- 1 vmail vmail 46940 2. Apr 06:20 dovecot.index.log.2 -rw------- 1 vmail vmail 91 18. Aug 2020 dovecot-keywords -rw------- 1 vmail vmail 65 2. Apr 18:37 .dovecot.lda-dupes drwx------ 5 vmail vmail 4096 2. Apr 18:37 .dovecot.lda-dupes.locks -rw------- 1 vmail vmail 6504 2. Apr 18:49 dovecot.list.index -rw------- 1 vmail vmail 3356 2. Apr 19:02 dovecot.list.index.log -rw------- 1 vmail vmail 2904 7. Jän 13:53 dovecot.mailbox.log -rw------- 1 vmail vmail 186894 2. Apr 18:59 dovecot-uidlist -rw------- 1 vmail vmail 8 7. Jän 13:53 dovecot-uidvalidity -r--r--r-- 1 vmail vmail 0 21. Apr 2020 dovecot-uidvalidity.5e9efc52 drwx------ 5 vmail vmail 4096 2. Apr 12:02 .Drafts drwx------ 5 vmail vmail 4096 12. Jun 2025 '.Entw&APw-rfe' drwx------ 5 vmail vmail 4096 6. Mai 2020 .Gesendet drwx------ 5 vmail vmail 4096 2. Apr 18:22 .INBOX.Administrator drwx------ 5 vmail vmail 4096 2. Apr 18:21 .INBOX.Alerts

[..]

We have

mail_home = /home/vmail/%{user | domain}/%{user}

I tried

mail_home = /home/vmail/%{user | domain}/%{user | username}

but that breaks things completely.

In 2.3 we had these namespaces:

namespace { type = private separator = / prefix = #location defaults to mail_location. inbox = yes }

namespace { type = public separator = / prefix = Oeffentlich/ location = maildir:/home/vmail/oeffentlich subscriptions = yes }

I tried "prefix = INBOX/" ... not good.

I share the config, a little bit anonymized, acls removed ...

doveconf -n

2.4.1-4 (7d8c0e5759): /etc/dovecot/dovecot.conf

Pigeonhole version 2.4.1-4 (0a86619f)

OS: Linux 6.12.74+deb13+1-amd64 x86_64 Debian 13.4

Hostname: xxxx

dovecot_config_version = 2.4.1 auth_allow_weak_schemes = yes auth_cache_size = 4M auth_debug = yes auth_mechanisms = plain login auth_verbose = yes default_process_limit = 300 dovecot_storage_version = 2.4.0 import_environment { CORE_ERROR = %{env:CORE_ERROR} CORE_OUTOFMEM = %{env:CORE_OUTOFMEM} LISTEN_FDS = %{env:LISTEN_FDS} LISTEN_PID = %{env:LISTEN_PID} MALLOC_MMAP_THRESHOLD_ = 131072 NOTIFY_SOCKET = %{env:NOTIFY_SOCKET} PATH = %{env:PATH} TZ = :/etc/localtime } info_log_path = /var/log/dovecot.info listen = * [::] log_path = /var/log/dovecot.log mail_debug = yes mail_driver = maildir mail_gid = 5000 mail_home = /home/vmail/%{user | domain}/%{user} mail_path = ~ mail_plugins { acl = yes notify = yes quota = no } mail_uid = 5000 protocols = imap sieve lmtp sieve_extensions { fileinto = yes reject = yes envelope = yes encoded-character = yes vacation = yes subaddress = yes comparator-i;ascii-numeric = yes relational = yes regex = yes imap4flags = yes copy = yes include = yes body = yes variables = yes enotify = yes environment = yes mailbox = yes date = yes index = yes ihave = yes duplicate = yes mime = yes foreverypart = yes extracttext = yes editheader = yes mboxmetadata = yes servermetadata = yes spamtest = yes spamtestplus = yes virustest = yes } sieve_global_extensions { vnd.dovecot.debug = yes vnd.dovecot.environment = yes vnd.dovecot.pipe = yes } sieve_pipe_bin_dir = /usr/lib/dovecot/sieve sieve_plugins = sieve_imapsieve sieve_extprograms sieve_spamtest_score_max_value = 15 sieve_spamtest_status_header = X-Spamd-Result: .*? \[([[:digit:]]+\.[[:digit:]]+) / [[:digit:]]+\.[[:digit:]]+\]; sql_driver = mysql ssl = required verbose_proctitle = yes mysql /var/run/mysqld/mysqld.sock { dbname = postfix_db password = # hidden, use -P to show it user = postfix_user } passdb sql { default_password_scheme = MD5-CRYPT query = SELECT username as user, password FROM mailbox WHERE ((username = '%{user | username}@domain1.at') OR (username = '%{user | username}@domain2.at')) AND active = '1' } userdb sql { iterate_query = SELECT userid AS username, domain FROM users query = SELECT username as user FROM mailbox WHERE ((username = '%{user | username}@domain1.at') OR (username = '%{user | username}@domain2.at') ) AND active = '1' } namespace inbox { inbox = yes prefix = separator = / type = private } namespace oeffentlich { mail_path = /home/vmail/oeffentlich prefix = Oeffentlich/ separator = / subscriptions = yes type = public mailbox Oeffentlich { acl

[DELETED for now]

} service imap-login { process_min_avail = 8 inet_listener imap { port = 0 ssl = no listen = } inet_listener imaps { port = 993 ssl = yes listen = } } service lmtp { extra_groups = $SET:default_internal_group user = vmail unix_listener /var/spool/postfix/private/dovecot-lmtp { group = postfix mode = 0660 user = postfix } } service imap { } service auth { client_limit = 1200 user = root unix_listener /var/spool/postfix/private/auth { group = postfix mode = 0666 user = postfix } unix_listener auth-client { group = postfix mode = 0660 user = postfix } unix_listener auth-userdb { mode = 0660 } } service auth-worker { } service dict { unix_listener dict { } } ssl_server { cert_file = /etc/letsencrypt/pfsense/cloud_imap_mail_smtp_LE_cert.fullchain key_file = /etc/letsencrypt/pfsense/cloud_imap_mail_smtp_LE_cert.key } protocol lda { mail_plugins = sieve } protocol imap { imap_idle_notify_interval = 29 mins mail_max_userip_connections = 50 mail_plugins { imap_acl = yes imap_quota = no imap_sieve = yes } } protocol lmtp { mail_plugins = sieve postmaster_address = logs@xunil.at } service managesieve-login { inet_listener sieve { port = 4190 } } service managesieve { } protocol sieve { managesieve_notify_capability = mailto managesieve_sieve_capability = fileinto reject envelope encoded-character vacation subaddress comparator-i;ascii-numeric relational regex imap4flags copy include variables body enotify environment mailbox date ihave } sieve_script personal { active_path = /home/vmail/%{user | domain}/%{user}/sieve/scripts/.dovecot.sieve driver = file path = /home/vmail/%{user | domain}/%{user}/sieve/scripts } sieve_script before-0 { driver = file path = /usr/lib/dovecot/sieve/global-spam.sieve type = before } service anvil { unix_listener anvil { group = $SET:default_internal_group mode = 0660 } }

I assume I am not far from full success, I'd just like to get rid of these errors because tomorrow dozens of users will access their mailboxes ...

Thanks for any pointers!