- dovecot - dovecot.org

dovecot submission Outlook issue
by Adrian M 30 Sep '26

30 Sep '26

Hello, I'm testing dovecot submission and I have some issues with Outlook clients. Thunderbird works without a hitch, only Outlook cannot send mails. If someone has seen this please let me know ! The log looks like this: Sep 28 09:36:12 mail dovecot: submission(user1)<1419><Ii0QSIVc2OvAqHBK>: Disconnected: Connection closed (unfinished QUIT command) (state=GREETING) in=44 out=81 Sep 28 09:37:23 mail dovecot: submission(user1)<4909><zOBITIVc6OfAqHBK>: Disconnected: Connection closed (unfinished QUIT command) (state=GREETING) in=44 out=81 My dovecot config has the following lines in local.conf: submission_relay_host = 127.0.0.1 submission_relay_port = 174 submission_relay_trusted = yes service submission-login { inet_listener submission { port = 587 } inet_listener submissions { port = 465 ssl = yes } } Hello, I'm testing dovecot submission and I have some issues with Outlook clients. Thunderbird works without a hitch, only Outlook cannot send mails. If someone has seen this please let me know ! The log looks like this: Sep 28 09:36:12 mail dovecot: submission(user1)<1419><Ii0QSIVc2OvAqHBK>: Disconnected: Connection closed (unfinished QUIT command) (state=GREETING) in=44 out=81 Sep 28 09:37:23 mail dovecot: submission(user1)<4909><zOBITIVc6OfAqHBK>: Disconnected: Connection closed (unfinished QUIT command) (state=GREETING) in=44 out=81 My dovecot config has the following lines in local.conf: submission_relay_host = 127.0.0.1 submission_relay_port = 174 submission_relay_trusted = yes service submission-login { inet_listener submission { port = 587 } inet_listener submissions { port = 465 ssl = yes } }

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Re: Migration to 2.4: Howto get the quota dict writing into a second DB
by Felipe Carneiro 28 Sep '26

28 Sep '26

Hello, This is regarding your message at https://dovecot.org/mailman3/archives/list/dovecot@dovecot.org/message/XW53… (I tried to reply on the thread but I don't have permission.) Were you able to get it working? I'm having the same problem with Dovecot 2.4. I've tried configuring it exactly as the documentation says, but I get this error when enabling the quota_clone plugin: *Error: quota_clone: dict_init_auto() failed: dict { .. } named list filter is missing* Same problem reported by other users: https://github.com/postfixadmin/postfixadmin/issues/935 Thanks in advance ! -- Best regards, Felipe Carneiro Hello, This is regarding your message at [1]https://dovecot.org/mailman3/archives/list/dovecot@dovecot.org/message/XW… (I tried to reply on the thread but I don't have permission.) Were you able to get it working? I'm having the same problem with Dovecot 2.4. I've tried configuring it exactly as the documentation says, but I get this error when enabling the quota_clone plugin: Error: quota_clone: dict_init_auto() failed: dict { .. } named list filter is missing Same problem reported by other users: [2]https://github.com/postfixadmin/postfixadmin/issues/935 Thanks in advance ! -- Best regards, Felipe Carneiro References Visible links 1. https://dovecot.org/mailman3/archives/list/dovecot@dovecot.org/message/XW53… 2. https://github.com/postfixadmin/postfixadmin/issues/935

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Dovecot 2.4.5 - Oath2 proxy
by Jerome Dalle 28 Sep '26

28 Sep '26

Hello I'm trying to set the pssdbb static (as describe in the documentation) to forward my oath2 authentication to backend Unfortunately, dovecot is unable to start with error: auth: Fatal: Cannot initialize oauth2: Missing oauth2_introspection_mode setting If anyone can help ? Thanks Hello I'm trying to set the pssdbb static (as describe in the documentation) to forward my oath2 authentication to backend Unfortunately, dovecot is unable to start with error: auth: Fatal: Cannot initialize oauth2: Missing oauth2_introspection_mode setting If anyone can help ? Thanks

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Dovecot Mailbox Viewer (Windows)
by jay＠designstack.co.uk 25 Sep '26

25 Sep '26

Hi Guys, I’ve been working on 'Dovecot Mailbox Viewer', a free, open-source Windows application for browsing Dovecot mdbox backups without setting up a Dovecot server. It started as a way to help a client access emails from a JetBackup/cPanel backup. You can open a .tar.gz archive or extracted folder, browse mailbox folders, search messages, view HTML emails, save attachments and export emails as pdf or .eml. The app is read-only and leaves the original backup untouched. Everything is processed locally, and remote images are blocked unless you choose to download them. There’s a standalone Windows executable available, so no Python installation is needed. Code, screenshots and downloads: https://github.com/DesignStack/Dovecot-Mailbox-Viewer It’s still early days, so feedback from the Dovecot community would be very welcome! Thanks! Jay

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Crash on FreeBSD 14.4 with dovecot 2.4.5
by Frank Volf 24 Sep '26

24 Sep '26

Hi, On a daily basis I see a anvil crash in my logs for dovecot 2.4.5 on FreeBSD. Not sure if this is a FreeBSD specific issue, a dovecot issue, or a configuration issue (this is the first system converted from 2.3 configuration syntax): Sep 9 03:20:00 mail dovecot[53730]: anvil: Panic: file anvil-connection.c: line 837: unreached Sep 8 16:40:00 mail dovecot[53730]: anvil: Panic: file anvil-connection.c: line 837: unreached Sep 7 20:47:28 mail dovecot[6215]: anvil: Panic: file anvil-connection.c: line 838 (anvil_connection_destroy): assertion failed: (hash_conn == conn) Sep 6 17:07:24 mail dovecot[96610]: anvil: Panic: file anvil-connection.c: line 837: unreached Sep 6 20:40:01 mail dovecot[96610]: anvil: Panic: file anvil-connection.c: line 837: unreached Sep 6 21:53:59 mail dovecot[96610]: anvil: Panic: file anvil-connection.c: line 837: unreached The "assertion failed" only happened once, but the "unreached" happen on a daily basis. About 20 minutes (more or less) after each crash I see also the following message: Sep 8 16:56:32 mail dovecot[53730]: anvil: Error: connect limit: disconnection for unknown (pid=59834, user=xxxx, service=imap, ip=x.x.x.x, conn_guid=7925eb292e15a06abae9000050df13ba) Can somebody please give me some pointers on how to solve or troubleshoot this? Kind regards, Frank Hi, On a daily basis I see a anvil crash in my logs for dovecot 2.4.5 on FreeBSD. Not sure if this is a FreeBSD specific issue, a dovecot issue, or a configuration issue (this is the first system converted from 2.3 configuration syntax): Sep 9 03:20:00 mail dovecot[53730]: anvil: Panic: file anvil-connection.c: line 837: unreached Sep 8 16:40:00 mail dovecot[53730]: anvil: Panic: file anvil-connection.c: line 837: unreached Sep 7 20:47:28 mail dovecot[6215]: anvil: Panic: file anvil-connection.c: line 838 (anvil_connection_destroy): assertion failed: (hash_conn == conn) Sep 6 17:07:24 mail dovecot[96610]: anvil: Panic: file anvil-connection.c: line 837: unreached Sep 6 20:40:01 mail dovecot[96610]: anvil: Panic: file anvil-connection.c: line 837: unreached Sep 6 21:53:59 mail dovecot[96610]: anvil: Panic: file anvil-connection.c: line 837: unreached The "assertion failed" only happened once, but the "unreached" happen on a daily basis. About 20 minutes (more or less) after each crash I see also the following message: Sep 8 16:56:32 mail dovecot[53730]: anvil: Error: connect limit: disconnection for unknown (pid=59834, user=xxxx, service=imap, ip=x.x.x.x, conn_guid=7925eb292e15a06abae9000050df13ba) Can somebody please give me some pointers on how to solve or troubleshoot this? Kind regards, Frank

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dict: ldap deref
by Tomas Habarta 23 Sep '26

23 Sep '26

Hello, just been testing sieve extlists against ldap dict in 2.4.5 -- works ok but need to narrow a search base but this would require setting deref other than default none for the ldap client. Seems that something like ldap_deref = always in dict_map {} section does not work (is not even documented, but config is parsed ok on the other hand) and value of the global ldap_deref is not picked up either. Question is whether the deref parameter is supposed to work and if yes, where to set it up correctly... Many thanks, Tomas

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fts-flatcurve: optimize can never complete once a shard holds an unreadable document
by Ihor Rusyn 23 Sep '26

23 Sep '26

Hello, ## Summary `fts_flatcurve_xapian_optimize_rebuild()` aborts on the first document whose termlist is missing, which makes shard compaction impossible for the affected folder from that point on. The failure is silent — the operation reports success — so shards accumulate without bound. We have seen folders reach several thousand shards, with an index orders of magnitude larger than the messages it covers. Present in 2.4.4, 2.4.5 and current main (checked at 732917749a). ## Symptom doveadm fts optimize -u <user> Error: fts-flatcurve: Optimize failed: DocNotFoundError: No termlist for document 257091 # exit code 0, shard count unchanged In production this is logged by indexer-worker and repeats every 20-30 minutes, once per delivery, each run leaving another shard behind. Affected folders also keep an `optimize` directory containing an empty Xapian database. ## Mechanism 1. Long-lived, high-churn folders end up with shards holding disjoint UID ranges. `db->compact()` with `DBCOMPACT_NO_RENUMBER` throws `InvalidOperationError`, which the code expects and handles. 2. It falls back to `fts_flatcurve_xapian_optimize_rebuild()`, which walks the MSet and copies each document into a fresh database. 3. `iter.get_document()` sits **outside** the try block. When a document in the MSet has no termlist it throws `DocNotFoundError`, which the local handler never sees. 4. The exception propagates to `fts_flatcurve_xapian_optimize_box_do()`, is caught by `catch (Xapian::Error &e)`, sets `failed = TRUE` — and that path does `return 0`. The caller therefore sees success. Old shards are never deleted, the merge never happens, and every subsequent message adds another shard. The folder can never recover on its own. ## Reproduction Reproducible from scratch in about five minutes on a scratch mailbox, with generated messages only. Three conditions have to coincide; raising uidnext alone does not reproduce it. U=test(a)example.com # 1. push uidnext past 2^31 doveadm mailbox update -u $U --min-next-uid 2277107224 INBOX # 2. + 3. churn: grow, index into many shards, expunge half. # the expunged messages leave their documents behind in older shards. for round in $(seq 1 10); do n=$(doveadm -f flow mailbox status -u $U messages INBOX | tail -1 | sed 's/.*messages=//') [ "$n" -gt 400 ] && n=400 doveadm copy -u $U INBOX mailbox INBOX 1:$n doveadm -o fts_flatcurve_rotate_count=25 index -u $U INBOX doveadm expunge -u $U mailbox INBOX 1:$((n/2)) done doveadm fts optimize -u $U Rounds 1-9 compact cleanly to 2 shards. The tenth breaks: 1,838 live messages, 84 shards, uidnext 2277110749 — and optimize then fails as above and never merges again. ## Suggested fix Move `get_document()` inside the try, and skip an unreadable document instead of aborting the rebuild. A document whose termlist is gone belongs to a message that no longer exists, so there is nothing to carry into the optimized database; the rebuild exists precisely to salvage databases the native compact refused. Patch attached (`fts-flatcurve-optimize-rebuild.diff`). Other `Xapian::Error` types keep aborting the rebuild, so genuine corruption is still not silently swallowed. Separately, the `return 0` on `failed` in `fts_flatcurve_xapian_optimize_box_do()` looks questionable regardless of this fix: a failed optimize is reported to the caller as success, which is why this went unnoticed for so long. ## Notes Affected folders are long-lived and high-churn: most of the UIDs they have issued belong to messages that were deleted years ago. Folders that compact normally stay at 9-11 shards, so the ones in this state stand out immediately by shard count alone — which is also the cheapest way to find them: find <index root> -type d -path '*/fts-flatcurve/*' -prune -printf '%h\n' \ | sort | uniq -c | sort -rn -- Best regards, Ihor Rusyn Hello, ## Summary `fts_flatcurve_xapian_optimize_rebuild()` aborts on the first document whose termlist is missing, which makes shard compaction impossible for the affected folder from that point on. The failure is silent -- the operation reports success -- so shards accumulate without bound. We have seen folders reach several thousand shards, with an index orders of magnitude larger than the messages it covers. Present in 2.4.4, 2.4.5 and current main (checked at 732917749a). ## Symptom doveadm fts optimize -u <user> Error: fts-flatcurve: Optimize failed: DocNotFoundError: No termlist for document 257091 # exit code 0, shard count unchanged In production this is logged by indexer-worker and repeats every 20-30 minutes, once per delivery, each run leaving another shard behind. Affected folders also keep an `optimize` directory containing an empty Xapian database. ## Mechanism 1. Long-lived, high-churn folders end up with shards holding disjoint UID ranges. `db->compact()` with `DBCOMPACT_NO_RENUMBER` throws `InvalidOperationError`, which the code expects and handles. 2. It falls back to `fts_flatcurve_xapian_optimize_rebuild()`, which walks the MSet and copies each document into a fresh database. 3. `iter.get_document()` sits **outside** the try block. When a document in the MSet has no termlist it throws `DocNotFoundError`, which the local handler never sees. 4. The exception propagates to `fts_flatcurve_xapian_optimize_box_do()`, is caught by `catch (Xapian::Error &e)`, sets `failed = TRUE` -- and that path does `return 0`. The caller therefore sees success. Old shards are never deleted, the merge never happens, and every subsequent message adds another shard. The folder can never recover on its own. ## Reproduction Reproducible from scratch in about five minutes on a scratch mailbox, with generated messages only. Three conditions have to coincide; raising uidnext alone does not reproduce it. U=[1]test(a)example.com # 1. push uidnext past 2^31 doveadm mailbox update -u $U --min-next-uid 2277107224 INBOX # 2. + 3. churn: grow, index into many shards, expunge half. # the expunged messages leave their documents behind in older shards. for round in $(seq 1 10); do n=$(doveadm -f flow mailbox status -u $U messages INBOX | tail -1 | sed 's/.*messages=//') [ "$n" -gt 400 ] && n=400 doveadm copy -u $U INBOX mailbox INBOX 1:$n doveadm -o fts_flatcurve_rotate_count=25 index -u $U INBOX doveadm expunge -u $U mailbox INBOX 1:$((n/2)) done doveadm fts optimize -u $U Rounds 1-9 compact cleanly to 2 shards. The tenth breaks: 1,838 live messages, 84 shards, uidnext 2277110749 -- and optimize then fails as above and never merges again. ## Suggested fix Move `get_document()` inside the try, and skip an unreadable document instead of aborting the rebuild. A document whose termlist is gone belongs to a message that no longer exists, so there is nothing to carry into the optimized database; the rebuild exists precisely to salvage databases the native compact refused. Patch attached (`fts-flatcurve-optimize-rebuild.diff`). Other `Xapian::Error` types keep aborting the rebuild, so genuine corruption is still not silently swallowed. Separately, the `return 0` on `failed` in `fts_flatcurve_xapian_optimize_box_do()` looks questionable regardless of this fix: a failed optimize is reported to the caller as success, which is why this went unnoticed for so long. ## Notes Affected folders are long-lived and high-churn: most of the UIDs they have issued belong to messages that were deleted years ago. Folders that compact normally stay at 9-11 shards, so the ones in this state stand out immediately by shard count alone -- which is also the cheapest way to find them: find <index root> -type d -path '*/fts-flatcurve/*' -prune -printf '%h\n' \ | sort | uniq -c | sort -rn -- Best regards, Ihor Rusyn References Visible links 1. mailto:test@example.com

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Upgraded to Dovecot 2.4 when I upgraded to Ubuntu 26.04. Now I can't get my existing emails.
by Ken Wright 23 Sep '26

23 Sep '26

I was afraid this would happen. I held off on upgrading to Dovecot 2.4 because of all the configuration changes, but I finally bit the bullet. I ran the conversion tool and it was okay as far as it went, but I'm still having problems. For the past three days I've been tweaking Dovecot's conf files, and I think I've finally got them to a working state, but my email client (Evolution) only shows me an empty inbox. No Drafts, no Junk, no Sent, and no Trash. Just an empty inbox. I'm sorry if I'm being redundant, but I'm quite frustrated. Here's the current output of doveconf -n: # 2.4.2 (0962ed2104): /etc/dovecot/dovecot.conf # Pigeonhole version 2.4.2 (767418c3) # OS: Linux 7.0.0-31-generic x86_64 Ubuntu 26.04.1 LTS # Hostname: localhost dovecot_config_version = 2.4.2 dovecot_storage_version = 2.4.2 fts_autoindex = yes fts_autoindex_max_recent_msgs = 999 fts_search_add_missing = yes listen = * mail_control_path = ~/ mail_driver = maildir mail_inbox_path = ~/ mail_index_path = ~/ mail_path = ~/ mail_privileged_group = mail mailbox_list_layout = maildir++ protocols { imap = yes lmtp = yes sieve = yes } sql_driver = mysql ssl = required mysql /var/run/mysqld/mysqld.sock { dbname = postfixadmin password = # hidden, use -P to show it user = postfix } passdb sql { default_password_scheme = ARGON2I driver = sql query = SELECT username AS user, password FROM mailbox WHERE username = '%{user | lower}' AND active = '1' mysql 127.0.0.1 { dbname = postfixadmin password = # hidden, use -P to show it user = postfix } } userdb sql { driver = sql iterate_query = SELECT username AS user FROM mailbox WHERE active = '1' query = SELECT CONCAT('/var/vmail/', maildir) AS home, 2000 AS uid, 2000 AS gid FROM mailbox WHERE username = '%{user | lower}' AND active = '1' mysql 127.0.0.1 { dbname = postfixadmin password = # hidden, use -P to show it user = postfix } } namespace inbox { inbox = yes prefix = separator = . type = private } service imap-login { inet_listener imap { port = 143 } inet_listener imaps { port = 993 ssl = yes } } service submission-login { inet_listener submission { } inet_listener submissions { } } service lmtp { unix_listener lmtp { mode = 0666 } unix_listener /var/spool/postfix/private/dovecot-lmtp { group = postfix mode = 0660 user = postfix } } service imap { vsz_limit = 1024M } service submission { } service auth { client_limit = 2048 unix_listener postfix-crypto-auth { group = postfix mode = 0666 user = postfix } } service auth-worker { } service dict { unix_listener dict { } } service stats { unix_listener stats-reader { group = www-data mode = 0660 user = www-data } unix_listener stats-writer { group = www-data mode = 0660 user = www-data } } protocol lda { mail_plugins = $mail_plugins sieve } protocol lmtp { mail_plugins = sieve } service managesieve-login { inet_listener sieve { port = 4190 } inet_listener sieve_deprecated { port = 2000 } } service managesieve { } ssl_server { cert_file = /etc/letsencrypt/live/subdomain.mydomain.tld/fullchain.pem key_file = /etc/letsencrypt/live/subdomain.mydomain.tld/privkey.pem } Help! Ken

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dovecot 2.4.5 imap process loop on folder deletion
by cesco 22 Sep '26

22 Sep '26

Hi imap process sometimes goes in infinite loop when deleting folders giving error: imap(user(a)mydomain.org)<996><EU1JPBZc3NisFAAC>: Couldn't create mailbox list lock /var/vmail_indexes/mydomain.org/user(a)mydomain.org/mailboxes.lock: file_create_locked(/var/vmail_indexes/mydomain.org/user@mydomain.org/mailbo… failed: fcntl(/var/vmail_indexes/mydomain.org/user@mydomain.org/mailboxes.lock, write-lock, F_SETLKW) locking failed: Timed out after 60 seconds (WRITE lock held by pid 316) dovecot is running inside a container based on debian 13 attached sysreport and gdb many thanks

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Mail loop storm
by Aki Tuomi 21 Sep '26

21 Sep '26

Hi! Unfortunately an ex-subscriber at hhad a catch-all/"MXGuardDog" spam-filter address that rewrites the recipient to the list posting address and re-sends. So every list message delivered there is immediately re-injected as a new post. We are taking steps to guard against this. Apologies for the extra emails. Regards Aki,

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