- dovecot - dovecot.org

Announcement: wormhole plugin, replication for Dovecot 2.4
by Patrick Cernko 12 Jun '26

12 Jun '26

Hello List, I am proud to announce my project "wormhole". This is an extension for Dovecot 2.4.1. It allows to continue the use of the replication feature of Dovecot that was removed with the 2.4 release. History: I started this project by forking the replication code of Dovecot 2.3.21.1 and porting it to 2.4. The first result was a patch for Dovecot 2.4.1. While working with the code, I realized that it is possible to provide the feature as a plugin / extension. In the first release of the plugin, I tried to integrate it with the existing dsync commands for doveadm. This required an API for access to the dsync commands, which I proposed to the Dovecot developers in https://github.com/dovecot/core/pull/249 . Unfortunately, my pull request was rejected, though I can understand the reasons for that. Without the required API, I had to switch to another approach: I forked the dsync code from doveadm to provide a new set of commands: "repl" and "repl-server". These commands work similar to "sync" and "dsync-server" but use additional functions required by the replication feature. This approach was released as version 0.3 of the plugin. With version 0.4 I renamed the project to wormhole. Before that it was just called dovecot-replication (see https://codeberg.org/errror/dovecot-replication) I thought that the project should have a more unique name. Currently I'm working on designing a test suite for wormhole. Doing unit tests of the components is not sufficient IMHO. The test suite should check the whole replication feature using two running dovecot instances that replicate the users' mailboxes. Having a sophisticated test suite will help in future development and bug tracking. The code can be found on my codeberg site at: https://codeberg.org/errror/wormhole There is also a web page on my personal homepage at: https://people.mpi-klsb.mpg.de/~pcernko/wormhole.shtml The project is still missing documentation. For the moment, configuration is similar to the existing Dovecot 2.3 documentation. Upgrading from 2.3: When using the included patch for Dovecot, the plugin should be 100% compatible with existing Dovecot 2.3 servers. This compatibility should allow uninterrupted upgrades of the service by replacing Dovecot on one server and then the other one. After the upgrade, the plugin can be reconfigured to work without the patch for Dovecot. Upgrading without the patch is also possible. During the upgrade (aka "while one server still runs 2.3") some aspects of the replication will not work or lack performance. Upgrading is not yet tested very well and missing documentation also. I will work on that soon. I hope to get some feedback, pull requests or bug reports via mail or at codeberg (preferred). -- Patrick Cernko <pcernko(a)mpi-klsb.mpg.de> +49 681 9325 5815 Joint Scientific IT and Technical Service Max-Planck-Institute für Informatik & Softwaresysteme

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New Backup Issue
by Doug Hardie 11 Jun '26

11 Jun '26

I have dovecot using maildir storage on the mail machine. I have an external drive directly connected to use a backup for the mailboxes. Doveadm backup works perfectly for this setup. I also have two external backup servers. Backup to those tends to fail with a variety of errors. I deleted the Maildir directory on the backup servers and created the original backups with doveadm backup. No issues were reported. However, the next backup generates errors: dsync-remote(jeanne)<HV6JE+i/KWo0NwAAq6l46g>: Warning: Deleting mailbox 'INBOX': UID=11166 GUID=1712570780.M604032P10319.mail,S=99689,W=101000 is missing locally dsync-remote(jeanne)<HV6JE+i/KWo0NwAAq6l46g>: Error: Couldn't delete mailbox INBOX: INBOX can't be deleted. dsync-local(jeanne)<HqU9Aei/KWoBMAAAZU03Dg>: Error: Remote command returned error 65: ssh sermons doveadm dsync-server -ujeanne -U dsync-remote(beneke)<eARRAem/KWpdNwAAq6l46g>: Warning: Deleting mailbox 'INBOX': UID=232 GUID=1641564460.M859673P8687.mail,S=5917,W=6035 is missing locally dsync-remote(beneke)<eARRAem/KWpdNwAAq6l46g>: Error: Couldn't delete mailbox INBOX: INBOX can't be deleted. dsync-local(beneke)<mw5bM+i/KWoJMAAAZU03Dg>: Error: Remote command returned error 65: ssh sermons doveadm dsync-server -ubeneke -U dsync-remote(doug)<6gmSJ+m/KWp7NwAAq6l46g>: Warning: Deleting mailbox 'INBOX': UID=92440 GUID=1465118975.V4eI7cfa32M232845.mail is missing locally dsync-remote(doug)<6gmSJ+m/KWp7NwAAq6l46g>: Error: Couldn't delete mailbox INBOX: INBOX can't be deleted. dsync-local(doug)<hwsCH+m/KWoNMAAAZU03Dg>: Error: Remote command returned error 65: ssh sermons doveadm dsync-server -udoug -U There is always one error per user, but they are different between the two backup machine. With the first error, I found the message 1712570780.M604032P10319.mail,S=99689,W=101000 in the mail server cur directory and deleted it. That messge did not exist in the backup server. I ran backup again and no issues. However, the next backup produced the following error: dsync-remote(jeanne)<dNWXGZbUKWoaOgAAq6l46g>: Warning: Deleting mailbox 'INBOX': UID=11167 GUID=1712574432.M425061P11306.mail,S=45149,W=45775 is missing locally dsync-remote(jeanne)<dNWXGZbUKWoaOgAAq6l46g>: Error: Couldn't delete mailbox INBOX: INBOX can't be deleted. dsync-local(jeanne)<Jg3tCZbUKWp5NQAAZU03Dg>: Error: Remote command returned error 65: ssh sermons doveadm dsync-server -ujeanne -U That message is in the cur directory on the mail server. It is not in the backup server. I don't understand the message that those files are missing locally (primary mail server I presume) when they are actually there and missing on the remote server. I don't know why they didn't get copied originally. The first email was recieved on Mon, 8 Apr 2024 so it can't be a timming issue. -- Doug

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Replication performance question and environment variables sanitization
by Jesus Cea 10 Jun '26

10 Jun '26

Hi, there. I am using dovecot 2.3.21.1. I am experimenting with replication, currently doing it manually, using this: doveadm -Dv sync -u jcea ssh email doveadm dsync-server -u prueba_backup; echo $? It works fine so far, but I have a few hundreds of mailboxes in my imap4 account and an "empty" (no changes) sync takes 30 seconds, since apparently it compare every mailbox (according to the debug info printed). I am using "mdbox" storage in both sides. I would expect an event replication, where time is proportional to the volume of changes, not to the total data volume or number of mailboxes. Am I doing anything wrong?. It would be faster to use "replicator" + "mail_replica". Can I improve this in some way? Replication must be both ways, because in one server new emails are arriving and in the other imapserver I am doing my mail work. I want new email appearing in my work imapserver (living my own laptop) and my email processing to be replicated back to the server for backup/disaster recovery (lost laptop, broken HD) and access from a different laptop, phone, etc. Thanks. PS: By default dovecot sanitizes the environment and doesn't allow "SSH_AUTH_SOCK" for ssh-agent. Why?. That is very inconvenient. I am using this environment variable to overcome that: DOVECOT_PRESERVE_ENVS="HOME USER SSH_AUTH_SOCK SSH_AGENT_PID LOG_STDERR_TIMESTAMP TZ CORE_OUTOFMEM CORE_ERROR" Is this the right way to do this? -- Jesús Cea Avión _/_/ _/_/_/ _/_/_/ jcea(a)jcea.es - https://www.jcea.es/ _/_/ _/_/ _/_/ _/_/ _/_/ Twitter: @jcea _/_/ _/_/ _/_/_/_/_/ jabber / xmpp:jcea@jabber.org _/_/ _/_/ _/_/ _/_/ _/_/ "Things are not so easy" _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ "My name is Dump, Core Dump" _/_/_/ _/_/_/ _/_/ _/_/ "El amor es poner tu felicidad en la felicidad de otro" - Leibniz

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dovecot 2.4 and Outlook
by Jochen Bern 08 Jun '26

08 Jun '26

Since I don't remember seeing *this* mentioned here so far, but *do* remember people asking about Outlook-dovecot compatibility issues every now and then, here's a potential cause for seeing more of those in the immediate future: https://fedoramagazine.org/fedora-43-upgrade-revealed-20-years-old-outlook-… Kind regards, -- Jochen Bern Systemingenieur Binect GmbH

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Using 2 LDAP sources for passdb
by Tom 03 Jun '26

03 Jun '26

I can't seem to find documentation that shows how to set up 2 LDAP passdb blocks. I can get each of them working properly, but only the second of the two works at any given time. I can't figure out the syntax needed to get both to work, even though I've been all over the Dovecot 2.4x official documentation. The docs seem to suggest settings that the server rejects. Anyone have any experience doing this, or know the correct syntax? Thanks in advance! passdb ldap { # works when standalone; fails when combined with 2nd block below #passdb_name = ldap1 #driver = ldap ldap_version = 3 bind = yes bind_userdn = %{user|username} ldap_auth_dn = cn=dovecot,ou=apps,dc=example,dc=com ldap_auth_dn_password = D0vec0t ldap_base = ou=apps,dc=foscore,dc=com ldap_uris = ldapi://%2Frun%2Fldapi filter = (&(objectClass=applicationProcess)(cn=%{user})) passdb_ldap_bind = yes passdb_ldap_bind_userdn = cn=%{user},ou=apps,dc=example,dc=com result_success = return-ok } passdb ldap { #driver = ldap #name = ldap_users ldap_version = 3 bind = yes bind_userdn = %{user|username} ldap_auth_dn = cn=dovecot,ou=apps,dc=example,dc=com ldap_auth_dn_password = D0vec0t ldap_base = ou=people,dc=example,dc=com ldap_uris = ldapi://%2Frun%2Fldapi filter = (&(objectClass=posixAccount)(uid=%{user|username})(memberOf=cn=mail,ou=%{user|domain},ou=groups,dc=example,dc=com)) passdb_ldap_bind = yes passdb_ldap_bind_userdn = uid=%{user|username},ou=people,dc=example,dc=com result_success = return-ok }

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Building on FreeBSD 14.4
by Frank Volf 03 Jun '26

03 Jun '26

Hi, I'm trying to build dovecot-2.4.4 on FreeBSD 14.4 and I get a strange error message. What I did is download and extract dovecot-2.4.4.tar.gz and then run ./configure without any arguments. After typing make the build started without any problems until this point: .... Making all in auth CC test_auth_cache-auth-cache.o CC test_auth_cache-test-auth-cache.o CC auth-main.o CC auth-auth.o CC auth-auth-cache.o CC auth-auth-client-connection.o CC auth-auth-master-connection.o CC auth-auth-policy.o CC auth-auth-penalty.o CC auth-auth-request.o CC auth-auth-request-fields.o CC auth-auth-request-handler.o CC auth-auth-request-var-expand.o CC auth-auth-sasl-mech-apop.o CC auth-auth-sasl-mech-dovecot-token.o CC auth-auth-sasl-mech-oauth2.o CC auth-auth-sasl.o CC auth-auth-settings.o CC auth-auth-fields.o CC auth-auth-token.o CC auth-auth-worker-connection.o CC auth-auth-worker-server.o CC auth-db-oauth2.o CC auth-db-sql.o CC auth-db-passwd-file.o CC auth-passdb.o CC auth-passdb-blocking.o CC auth-passdb-bsdauth.o CC auth-passdb-cache.o CC auth-passdb-oauth2.o CC auth-passdb-passwd.o CC auth-passdb-passwd-file.o CC auth-passdb-pam.o CC auth-passdb-sql.o CC auth-passdb-static.o CC auth-userdb.o CC auth-userdb-blocking.o CC auth-userdb-passwd.o CC auth-userdb-passwd-file.o CC auth-userdb-prefetch.o CC auth-userdb-static.o CC auth-userdb-sql.o CC auth-db-ldap.o CC auth-db-ldap-sasl.o CC auth-db-ldap-settings.o CC auth-passdb-ldap.o CC auth-userdb-ldap.o CC auth-db-lua.o CC auth-passdb-lua.o CC auth-userdb-lua.o make[3]: don't know how to make -L/usr/local/lib. Stop make[3]: stopped making "all" in /home/volf/dovecot-2.4.4/src/auth *** Error code 1 So, apparently make is confused and thinks that the compiler/linker commandline option is an item to build. I'm at loss how to solve this. I would appreciate it, if somebody could give me a hint how to solve this. Kind regards, Frank Hi, I'm trying to build dovecot-2.4.4 on FreeBSD 14.4 and I get a strange error message. What I did is download and extract dovecot-2.4.4.tar.gz and then run ./configure without any arguments. After typing make the build started without any problems until this point: .... Making all in auth CC test_auth_cache-auth-cache.o CC test_auth_cache-test-auth-cache.o CC auth-main.o CC auth-auth.o CC auth-auth-cache.o CC auth-auth-client-connection.o CC auth-auth-master-connection.o CC auth-auth-policy.o CC auth-auth-penalty.o CC auth-auth-request.o CC auth-auth-request-fields.o CC auth-auth-request-handler.o CC auth-auth-request-var-expand.o CC auth-auth-sasl-mech-apop.o CC auth-auth-sasl-mech-dovecot-token.o CC auth-auth-sasl-mech-oauth2.o CC auth-auth-sasl.o CC auth-auth-settings.o CC auth-auth-fields.o CC auth-auth-token.o CC auth-auth-worker-connection.o CC auth-auth-worker-server.o CC auth-db-oauth2.o CC auth-db-sql.o CC auth-db-passwd-file.o CC auth-passdb.o CC auth-passdb-blocking.o CC auth-passdb-bsdauth.o CC auth-passdb-cache.o CC auth-passdb-oauth2.o CC auth-passdb-passwd.o CC auth-passdb-passwd-file.o CC auth-passdb-pam.o CC auth-passdb-sql.o CC auth-passdb-static.o CC auth-userdb.o CC auth-userdb-blocking.o CC auth-userdb-passwd.o CC auth-userdb-passwd-file.o CC auth-userdb-prefetch.o CC auth-userdb-static.o CC auth-userdb-sql.o CC auth-db-ldap.o CC auth-db-ldap-sasl.o CC auth-db-ldap-settings.o CC auth-passdb-ldap.o CC auth-userdb-ldap.o CC auth-db-lua.o CC auth-passdb-lua.o CC auth-userdb-lua.o make[3]: don't know how to make -L/usr/local/lib. Stop make[3]: stopped making "all" in /home/volf/dovecot-2.4.4/src/auth *** Error code 1 So, apparently make is confused and thinks that the compiler/linker commandline option is an item to build. I'm at loss how to solve this. I would appreciate it, if somebody could give me a hint how to solve this. Kind regards, Frank

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Re: User authentication for shared mailbox
by Stéphane Veyret 31 May '26

31 May '26

I managed to make it work. In case some other people want to do the same, the trick was to use the master user concept, as suggested by Aki Tuomi, with a lua script to check if user can be master. My configuration looks like this: passdb pam_master { driver = pam master = yes result_success = continue } passdb pam { } passdb lua { lua_file = /etc/dovecot/master-auth.lua result_failure = return-fail result_internalfail = return-fail result_success = continue-ok } passdb ldap { ldap_base = ou=Group,dc=example,dc=com fields { password = {SHA1}IQ== user = %{ldap:cn} } filter = (cn=%{user | username}) } and the lua script: function script_init() return 0 end function auth_passdb_lookup(req) if req.master_user then req:log_info("Looking for groups for " .. tostring(req.master_user)) handle = io.popen("/bin/groups " .. tostring(req.master_user)) output = handle:read("*a") req:log_debug("Searching " .. tostring(req.user) .. " in found groups " .. output) for group in output:gmatch("%w+") do if group == req.user then return dovecot.auth.PASSDB_RESULT_OK, { password="!" } end end end return dovecot.auth.PASSDB_RESULT_USER_UNKNOWN, "No such user" end -- Bien cordialement, / Plej kore, Stéphane Veyret I managed to make it work. In case some other people want to do the same, the trick was to use the master user concept, as suggested by Aki Tuomi, with a lua script to check if user can be master. My configuration looks like this: passdb pam_master { driver = pam master = yes result_success = continue } passdb pam { } passdb lua { lua_file = /etc/dovecot/master-auth.lua result_failure = return-fail result_internalfail = return-fail result_success = continue-ok } passdb ldap { ldap_base = ou=Group,dc=example,dc=com fields { password = {SHA1}IQ== user = %{ldap:cn} } filter = (cn=%{user | username}) } and the lua script: function script_init() return 0 end function auth_passdb_lookup(req) if req.master_user then req:log_info("Looking for groups for " .. tostring(req.master_user)) handle = io.popen("/bin/groups " .. tostring(req.master_user)) output = handle:read("*a") req:log_debug("Searching " .. tostring(req.user) .. " in found groups " .. output) for group in output:gmatch("%w+") do if group == req.user then return dovecot.auth.PASSDB_RESULT_OK, { password="!" } end end end return dovecot.auth.PASSDB_RESULT_USER_UNKNOWN, "No such user" end -- Bien cordialement, / Plej kore, Stephane Veyret

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dsync between 2.3.16 and 2.4.2
by Jean-Daniel Beaubien 28 May '26

28 May '26

Hi, I currently have a doveadm backup running my prod and backup server. Both are currently running 2.3.16, and the following command runs fine: sudo doveadm -v backup -u XXXX -P remote:XXXX@192.168.111.XX I am in the process of updating my servers to ubuntu 26.04 which runs dovecot 2.4.2 and I am running into problems trying to run this command. For some reason, it tries to delete the INBOX on the destination and I get the following error: dsync-remote(XXXX)<7hkbKDl6F2rlxQAArPp36Q>: Error: brain S: Mailbox INBOX sync: mailbox_delete failed: The /private/specialuse attribute cannot be changed doveadm(228686): Error: Remote command returned error 65: ssh -lXXXX 192.168.111.XX doveadm dsync-server -uXXXX I am not sure what/why this is happening. I read the docs and man page, but could not find a solution. Anyone knows what is happening, and how to solve this? Thanks, -JD ----- Addendum ----- Another thing that might help someone else: I had to add a line to the config file to avoid the -U problem: dsync_remote_cmd = "ssh -l%{login} %{host} doveadm dsync-server -u%{user}" This seems to already be solved ( https://dovecot.org/mailman3/archives/list/dovecot@dovecot.org/thread/B3TQF…) but not yet in the ubuntu 26.04 release? Hi, I currently have a doveadm backup running my prod and backup server. Both are currently running 2.3.16, and the following command runs fine: sudo doveadm -v backup -u XXXX -P remote:XXXX@192.168.111.XX I am in the process of updating my servers to ubuntu 26.04 which runs dovecot 2.4.2 and I am running into problems trying to run this command. For some reason, it tries to delete the INBOX on the destination and I get the following error: dsync-remote(XXXX)<7hkbKDl6F2rlxQAArPp36Q>: Error: brain S: Mailbox INBOX sync: mailbox_delete failed: The /private/specialuse attribute cannot be changed doveadm(228686): Error: Remote command returned error 65: ssh -lXXXX 192.168.111.XX doveadm dsync-server -uXXXX I am not sure what/why this is happening. I read the docs and man page, but could not find a solution. Anyone knows what is happening, and how to solve this? Thanks, -JD ----- Addendum ----- Another thing that might help someone else: I had to add a line to the config file to avoid the -U problem: dsync_remote_cmd = "ssh -l%{login} %{host} doveadm dsync-server -u%{user}" This seems to already be solved ([1]https://dovecot.org/mailman3/archives/list/dovecot@dovecot.org/thread/B3T…) but not yet in the ubuntu 26.04 release? References Visible links 1. https://dovecot.org/mailman3/archives/list/dovecot@dovecot.org/thread/B3TQF…

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I can't find up to date documentation about dovecot authentication process design
by kristoffermollerhoj＠gmail.com 27 May '26

27 May '26

Hi, I am currently about to port a legacy / custom authentication mechanism from 2.3 to 2.4. Many things have changed in this area, and I have unfortunately not been able to find any valid documentation about this topic. I have looked here: https://doc.dovecot.org/2.4.4/developers/design/auth_process.html but as far as I can see all the content is about the code design for dovecot 2.3, not 2.4. Just to mention a few examples: There is not anymore a struct named mech_module, there is no such file as mech.h, and also the API for the central callback functions such as auth_new() and auth_initial() seems to have changed a lot (both arguments and return types). Maybe a somewhat unfinished version of the documentation can be found on a specific branch? Thank you, Kristoffer Møllerhøj.

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Sent, Junk and Drafts are not created
by Thomas Jensen 26 May '26

26 May '26

I have a new dovecot 2.4.2 setup. All seems to work fine, except Sent, Junk and Drafts are not created. In 15-mailboxes.conf I have: namespace inbox { # These mailboxes are widely used and could perhaps be created automatically: mailbox Drafts { auto = create special_use = \Drafts } mailbox Junk { auto = create special_use = \Junk } mailbox Trash { auto = create special_use = \Trash } # For \Sent mailboxes there are two widely used names. We'll mark both of # them as \Sent. User typically deletes one of them if duplicates are created. mailbox Sent { auto = create special_use = \Sent } mailbox "Sent Messages" { auto = create special_use = \Sent } } But nothing is created. And dovecot -n return this: (note the "\\") root@rpix:~# dovecot -n # 2.4.2 (0962ed2104): /etc/dovecot/dovecot.conf # Pigeonhole version 2.4.2 (767418c3) # OS: Linux 7.0.0-15-generic x86_64 Ubuntu 26.04 LTS # Hostname: rpix.dk # 9 default setting changes since version 2.4.0 dovecot_config_version = 2.4.0 auth_default_domain = rpix.dk auth_mechanisms = plain login auth_username_format = %{user|lower} dovecot_storage_version = 2.4.0 fts_autoindex = yes fts_autoindex_max_recent_msgs = 999 fts_search_add_missing = yes mail_driver = maildir mail_home = /var/vmail/%{user | domain}/%{user | username} mail_path = ~/Maildir mail_privileged_group = mail protocols = imap lmtp sql_driver = mysql ssl = required passdb sql { default_password_scheme = ARGON2I query = SELECT username AS user,password FROM mailbox WHERE username = '%{user}' AND active='1' } userdb sql { iterate_query = SELECT username AS user FROM mailbox query = SELECT 2000 AS uid, 2000 AS gid FROM mailbox WHERE username = '%{user}' AND active='1' } mysql localhost { dbname = postfixadmin password = # hidden, use -P to show it user = postfixadmin } namespace inbox { inbox = yes mailbox Drafts { auto = create special_use = "\\Drafts" } mailbox Junk { auto = create special_use = "\\Junk" } mailbox Trash { auto = create special_use = "\\Trash" } mailbox Sent { auto = create special_use = "\\Sent" } mailbox "Sent Messages" { auto = create special_use = "\\Sent" } } service imap-login { inet_listener imap { } inet_listener imaps { } } service pop3-login { inet_listener pop3 { } inet_listener pop3s { } } service submission-login { inet_listener submission { } inet_listener submissions { } } service lmtp { unix_listener /var/spool/postfix/private/dovecot-lmtp { group = postfix mode = 0600 user = postfix } } service imap { } service pop3 { } service submission { } service auth { unix_listener /var/spool/postfix/private/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 } } ssl_server { cert_file = /etc/letsencrypt/live/mail/fullchain.pem key_file = /etc/letsencrypt/live/mail/privkey.pem prefer_ciphers = server } protocol lmtp { auth_username_format = %{user | lower} } What am I doing wrong? -- /Thomas Jensen, Denmark

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