March 2026 - dovecot - dovecot.org

Broken table in dovecot-pw manual
by Célestin Matte 01 Apr '26

01 Apr '26

Hello, I just noticed while reading the dovecot-pw man on Arch Linux that the table in the -r option is broken (missing newline between row): | Scheme | Minimum | Maximum | Default | | ------ | ------- | ------- | ------- | | BLF-CRYPT | 4 | 31 | 5 | | SHA256-CRYPT | 1000 | 999999999 | 5000 | | SHA512-CRYPT | 1000 | 999999999 | 5000 | Regards, -- Célestin Matte

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cannot get IOS or MacOSX to connect to dovecot:995 since upgraded Mac or iPhone
by Bill Scheding 01 Apr '26

01 Apr '26

Versions: [wls(a)www.wls.org]$ uname -a Linux www.wls.org 3.10.0-1160.119.1.el7.x86_64 #1 SMP Tue Jun 4 14:43:51 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux [wls(a)ww.wls.org]$ dovecot --version 2.2.36 (1f10bfa63) My Certs: Testing cert dovecot.key unable to load certificate 139668060415888:error:0906D06C:PEM routines:PEM_read_bio:no start line:pem_lib.c:707:Expecting: TRUSTED CERTIFICATE lrwxrwxrwx 1 root root 21 Mar 25 15:44 dovecot.key -> dovecot.key.old_sep_2 Testing chain dovecot.pem SHA1 Fingerprint=4A:29:34:1D:D5:9C:67:59:FA:31:7E:FF:F4:53:F8:DB:25:73:15:07 subject= /OU=IMAP server/CN=imap.example.com/emailAddress=postmaster@example.com issuer= /OU=IMAP server/CN=imap.example.com/emailAddress=postmaster@example.com serial=C8AA4C688A3F2638 b5bd7939 notBefore=Sep 2 20:17:33 2018 GMT notAfter=Sep 2 20:17:33 2019 GMT lrwxrwxrwx 1 root root 21 Mar 25 15:44 dovecot.pem -> dovecot.crt.old_sep_2 New Certs: Testing key ca.key.3.13.4 RSA key ok lrwxrwxrwx 1 root root 31 Mar 13 14:14 ca.key.3.13.4 -> ../../tls/private/ca.key.3.13.4 Testing chain ca.crt.3.13.4 SHA1 Fingerprint=79:69:88:2A:E0:BF:58:A8:21:E3:88:12:8D:45:20:4F:FD:68:33:63 subject= /C=XX/ST= /L= /O= /OU=IMAP server/CN=imap.example.com/emailAddress=postmaster@example.com issuer= /C=XX/ST= /L= /O= /OU=IMAP server/CN=imap.example.com/emailAddress=postmaster@example.com serial=B912DD19FEDC441C 402b4e2a notBefore=Mar 13 20:02:58 2026 GMT notAfter=Mar 13 20:02:58 2027 GMT lrwxrwxrwx 1 root root 29 Mar 13 14:13 ca.crt.3.13.4 -> ../../tls/certs/ca.crt.3.13.4 They install OK, dovecot starts; but iPhone and mac cannot connect to pop3 Cannot get my iPhone or Mac to accept new certs from lets encrypt, et. al. This is a new problem, started recently. My existing cert expired in 2016 William

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Variable expansion syntax: Filter "default" throws error (unwanted)
by Johannes Nohl 01 Apr '26

01 Apr '26

I am using dovecot 2.4.2 (almost) with new config language and I have a working configuration. However, the check for disabled users throws permanently errors in the log file, whenever a user is missing the ldap attribute for disabled. This is - in my view - due to a misfunction of Filter "default". passdb ldap { driver = ldap ldap_bind = yes ldap_filter = (&(|(objectClass=posixAccount)(objectClass=mailAccount))(uid=%{user})) fields { user = %{ldap:uid} nologin = %{ldap:shadowInactive | default(null)} reason = The account for this email address is disabled. } } This results in the following log line: 2026-03-31T00:46:31.102690+02:00 mailserver dovecot: auth(test,ipv4,sasl:plain)<YE81n0VOVuofEeSD>: Error: ldap: auth_passdb_post settings: Failed to parse configuration: Failed to expand passdb_fields/nologin setting variables: ldap: No such attribute 'shadowinactive' The right behaviour would be no logging on login success. Because the Filter "default" is intended to suppress any errors ("When value is missing or empty, you can use the default filter to provide value. Missing variables will cause errors and must be negated with default. This does not apply to all providers, some providers return empty when value is missing."). https://doc.dovecot.org/2.4.2/core/settings/variables.html#variable-expansi… As you may have seen I had to borrow null-value from sql db config also to make nologin ignoring a non present attribute. This is undocumented obviously. Instead, a non-working tip is provided ("Changed: 2.4.0 Extra fields can now also be set to empty string, "). However, the following does not work: "nologin = {ldap:shadowinactive | default("")}". https://doc.dovecot.org/2.4.2/core/settings/variables.html Also, the documentation is missing/hiding the part which explains that "default()" can be used to avoid error logs. PR regarding the documentation source is sent already. See "Fails if the attribute is not present, unless the ` <missing part>" https://doc.dovecot.org/2.4.0/core/config/auth/databases/ldap.html#ldap-spe… Is there another way to verify if account is disabled? -- Johannes Nohl postmaster i-t-cloud -- Johannes Nohl postmaster(a)i-t-cloud.de I am using dovecot 2.4.2 (almost) with new config language and I have a working configuration. However, the check for disabled users throws permanently errors in the log file, whenever a user is missing the ldap attribute for disabled. This is - in my view - due to a misfunction of Filter "default". passdb ldap { driver = ldap ldap_bind = yes ldap_filter = (&(|(objectClass=posixAccount)(objectClass=mailAccount))(uid=%{user})) fields { user = %{ldap:uid} nologin = %{ldap:shadowInactive | default(null)} reason = The account for this email address is disabled. } } This results in the following log line: *2026-03-31T00:46:31.102690+02:00 mailserver dovecot: auth(test,ipv4,sasl:plain)<YE81n0VOVuofEeSD>: Error: ldap: auth_passdb_post settings: Failed to parse configuration: Failed to expand passdb_fields/nologin setting variables: ldap: No such attribute 'shadowinactive' The right behaviour would be no logging on login success. Because the Filter "default" is intended to suppress any errors ("When value is missing or empty, you can use the default filter to provide value. Missing variables will cause errors and must be negated with default. This does not apply to all providers, some providers return empty when value is missing."). https://doc.dovecot.org/2.4.2/core/settings/variables.html#variable-expansi… As you may have seen I had to borrow null-value from sql db config also to make nologin ignoring a non present attribute. This is undocumented obviously. Instead, a non-working tip is provided ("Changed: 2.4.0 Extra fields can now also be set to empty string, "). However, the following does not work: "nologin = {ldap:shadowinactive | default("")}". https://doc.dovecot.org/2.4.2/core/settings/variables.html Also, the documentation is missing/hiding the part which explains that "default()" can be used to avoid error logs. PR regarding the documentation source is sent already. See "Fails if the attribute is not present, unless the ` <missing part>" https://doc.dovecot.org/2.4.0/core/config/auth/databases/ldap.html#ldap-spe… Is there another way to verify if account is disabled? -- Johannes Nohl postmaster i-t-cloud -- Johannes Nohl postmaster(a)i-t-cloud.de

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Dovecot and Pigeonhole v2.4.3 released
by Aki Tuomi 31 Mar '26

31 Mar '26

Hi! We are happy to publish version 2.4.3 of Dovecot and Pigeonhole. These contain several CVEs, discovered by external researches. The majority of these have been discovered with help of automated code analysis tools like claude code security, which is why some of these are rather old, missed bugs. No new supported distros have been added or old removed, no new dependencies have been added. Note that there are experimental features in 2.4, one is enabled with `--enable-experimental-mail-utf8`, and another with `--enable-experimental-imap4rev2`, and you also need to set mail_utf8_extensions=yes and imap4rev2_enabled=yes to enable them in config. https://dovecot.org/releases/2.4/dovecot-2.4.3.tar.gz https://dovecot.org/releases/2.4/dovecot-2.4.3.tar.gz.sig https://pigeonhole.dovecot.org/releases/2.4/dovecot-pigeonhole-2.4.3.tar.gz https://pigeonhole.dovecot.org/releases/2.4/dovecot-pigeonhole-2.4.3.tar.gz… Binary packages in https://repo.dovecot.org/ Docker images in https://hub.docker.com/r/dovecot/dovecot --- * CVE-2025-59028: Invalid base64 authentication can cause DoS for other logins. * CVE-2025-59031: decode2text.sh OOXML extraction may follow symlinks and read unintended files during indexing. Fixed by dropping the script. * CVE-2026-24031: SQL injection possible if auth_username_chars is configured empty. Fixed escaping to always happen. v2.4 regression. * CVE-2026-27859: Excessive RFC 2231 MIME parameters in email would cause excessive CPU usage. Fixed by limiting number of parameters to process. * CVE-2026-27860: LDAP query injection possible if auth_username_chars is configured empty. Fixed escaping to always happen. v2.4 regression. * CVE-2026-27857: Sending excessive parenthesis causes imap-login to use excessive memory. * CVE-2026-27856: Doveadm credentials were not checked using timing-safe checking function. * CVE-2026-27855: OTP driver vulnerable to replay attack. * Remove default service/*/service_extra_groups=$SET:default_internal_group. They are now replaced by default mail_access_groups=$SET:default_internal_group. * The version file has been renamed as version.txt to avoid clash with C++ headers. * auth: oauth2 - Do not export token automatically, must be exported using fields. * config: Don't accept 0 as meaning unlimited anymore for last_valid_uid, last_valid_gid, mail_cache_max_headers_count, mail_cache_max_header_name_length, mail_vsize_bg_after_count, mail_sort_max_read_count, message_max_size, submission_max_recipients and quota_mail_size. * imap, pop3: Don't autoexpunge if Dovecot is shutting down or process is killed. * imap: LIST - Handle invalid mUTF-7 mailbox names as never matching anything * lazy-expunge: Change lazy_expunge_only_last_instance default to yes. * lda: Use EX_TEMPFAIL (75) if configuration is invalid instead of 89. v2.4 regression. * lib-master: Increase ANVIL_DEFAULT_LOOKUP_TIMEOUT_MSECS from 5s to 30s * lib: crc32 - Use zlib's built-in CRC32 function + Improve UTF-8 support for mail storage. + auth: Add default auth-token UNIX socket for token-based authentication. + doc: solr-config-9.xml - Make it compatible with Solr 9.8.0 + doveadm: dsync - Search mails when exporting to reduce number of mails exported by dsync-server. + dovecot-sysreport: Add -D|--destdir support. + imap, imap-hibernate: Use DOVECOT-TOKEN authentication for unhibernation. Default imap-master socket permissioms have been changed due to this. + imap: Add APPENDLIMIT capability when configured with quota_mail_size. + imap: Support STATUS (DELETED) for IMAP4rev2. + imapc: Add support for SEARCH MIMEPART + imapc: Improve error forwarding. + imapc: Support SORT and ESORT extensions. + imapc: Support STATUS (DELETED) for IMAP4rev2. + lib-sql: Support parameterized queries. + lib-test: Add new test-dir API for better temporary test directory handling. + lmtp: Advertize SIZE capability when configured with quota_mail_size. + lmtp: Support XCLIENT DESTADDR and DESTPORT + pop3-login: proxy - Add support for XCLIENT DESTIP and DESTPORT + submission-login: proxy - Add support for XCLIENT DESTIP and DESTPORT + Various optimizations have been made to the code. - Fix building dovecot with BSD, Solaris and macOS. - auth: Crash would occur if users were iterated but userdb_ldap_iterate_fields was not set. - auth: Fix request leak when client authenticates with unsupported mechanism. - auth: Some passdbs would default to PLAIN instead of CRYPT scheme. - config: Section and setting names could have been intermixed, resulting in the setting being silently ignored. - configure: Fix checking if BUILD_IMAP_HIBERNATE is set - doveadm: dsync - -e parameter was handled wrong with dsync-server. - fts-flatcurve: Mailbox leak would occur if mailbox failed to open. - imap: Fix potential issues with unhibernation and process state handling. - imapc: SEARCH failure handling was done wrong. - imapc: UID STORE commands included extra comma in uidset. - lib-auth-client: auth-master - Fix panic when reconnecting after handshake timeout. - lib-compression: Lz4 algorithm would assert-crash with malicious data. - lib-dcrypt: Fix digest algorithm handling. - lib-dict: Escape username paths to prevent traversal issues with dict-fs. - lib-http: Fix HTTP parsing edge cases and state handling. - lib-iostream: Disallow empty ssl_min_protocol. - lib-json: Fix incorrect character handling logic. - lib-ldap: Fix various TLS related bugs. - lib-mail: Fix charset translation and MIME parsing edge cases. - lib-mail: Fix multiple bounds checks and parsing issues in message handling. - lib-var-expand: Multiple fixes and improvements for expansion handling. - lib: Fix punycode decoding out-of-bounds reads. - lib: Fix unicode normalization edge cases causing crashes. - lib-http: Chunked transfer trailer size was not limited. - login-common: Improve logging and internal error handling. - login-common: login_log_format_elements was split by spaces naively, which could break variable expansion. Use template aware splitting now. - master: Dovecot would fail to start if listen directive was used and dovenull or dovecot user was missing. - pop3c: Connection might've hung with SSL. - util: Fix handling of environment variables containing control characters. - Many other bugs have been fixed. --- * CVE-2026-27858: managesieve-login can allocate large amount of memory during authentication. * CVE-2025-59032: ManageSieve panic occurs with sieve-connect as a client. * lib-sieve: Don't accept 0 as meaning unlimited anymore for sieve_quota_script_count and sieve_quota_storage_size. * managesieve-login: If mail_max_userip_connections is reached, return LIMIT/CONNECTIONS resp-code. * managesieve-login: proxy - Return unexpected backend failures as TRYLATER/NORETRY resp-code. * managesieve: Remove default service_extra_groups=$SET:default_internal_group. + managesieve-login: proxy - Add support for XCLIENT DESTIP and DESTPORT. - imapsieve: Fix panic occurring upon implicit flag changes. - lib-sieve: include-extension - Fix crash occurring when previous global command has no arguments. - lib-sieve: Fix erroneous attempt to read active script for non-personal storage. - lib-sieve: ldap: Fix linking non-shared LIBDOVECOT.

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migration from 2.3 to 2.4 : postfix can't deliver via lmtp
by Stefan G. Weichinger 31 Mar '26

31 Mar '26

I am in the process of upgrading and rewriting my config. I can access IMAP etc ... so my database access is working. I have issues with LMTP: postfix can't deliver to dovecot. The postfix-confiog wasn't touched at all. the error: Mar 27 11:46:37 co dovecot: auth(stefan(a)oops.co.at): Error: userdb: client doesn't have lookup permissions for this user: userdb reply doesn't contain uid (to bypass this check, set: service auth { unix_listener /run/dovecot/auth-userdb { mode=0777 } }) What I don't understand: I configure this: service auth { unix_listener /var/spool/postfix/private/auth { group = postfix mode = 0666 user = postfix } } service auth-worker { user = postfix } service lmtp { user = vmail unix_listener /var/spool/postfix/private/dovecot-lmtp { group = postfix mode = 0660 user = postfix } } protocol lmtp { mail_plugins = sieve postmaster_address = logs(a)xunil.at } And in postfix: virtual_transport = lmtp:unix:private/dovecot-lmtp virtual_uid_maps = static:5000 virtual_gid_maps = static:5000 local_transport = virtual local_recipient_maps = $virtual_mailbox_maps smtpd_sasl_auth_enable = yes smtpd_sasl_type = dovecot smtpd_sasl_path = private/auth Where does "/run/dovecot/auth-userdb" come from? I understand that according to my config /var/spool/postfix/private/auth should be used? ls /var/spool/postfix/private/auth -l srw-rw-rw- 1 postfix postfix 0 Mar 27 11:45 /var/spool/postfix/private/auth ls /var/spool/postfix/private/dovecot-lmtp -l srw-rw---- 1 postfix postfix 0 Mar 27 11:45 /var/spool/postfix/private/dovecot-lmtp I'd appreciate any quick help here ... while googling and testing around ... thanks!

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upgrade to 2.4
by John Hill 31 Mar '26

31 Mar '26

Dovecot may go down as one of the best/worst software in its category. I'm staying on Debian 12 doing backports, till the dust settles several times. --john

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Fwd: dovecot mailing list probe message
by Jaco Kroon 30 Mar '26

30 Mar '26

Hi, It seems like the list system is breaking DKIM - triggering bounces, resulting in unsuscribes. Is there recommendations on how to deal with this? Looks like it relates 100% to the addition of the footer: ______________________________________________ dovecot mailing list -- dovecot(a)dovecot.org To unsubscribe send an email to dovecot-leave(a)dovecot.org Kind regards, Jaco -------- Forwarded Message -------- Subject: dovecot mailing list probe message Date: Mon, 30 Mar 2026 06:32:58 +0000 From: dovecot-bounces+a190cb9ae5d94d8fa6e2af68fc964a7aaa13256b(a)dovecot.org To: jaco(a)uls.co.za This is a probe message. You can ignore this message. The dovecot(a)dovecot.org mailing list has received a number of bounces from you, indicating that there may be a problem delivering messages to jaco(a)uls.co.za. A sample is attached below. Please examine this message to make sure there are no problems with your email address. You may want to check with your mail administrator for more help. You don't need to do anything to remain an enabled member of the mailing list. If you have any questions or problems, you can contact the mailing list owner at dovecot-owner(a)dovecot.org Hi, It seems like the list system is breaking DKIM - triggering bounces, resulting in unsuscribes. Is there recommendations on how to deal with this? Looks like it relates 100% to the addition of the footer: ______________________________________________ dovecot mailing list -- [1]dovecot(a)dovecot.org To unsubscribe send an email to [2]dovecot-leave(a)dovecot.org Kind regards, Jaco -------- Forwarded Message -------- Subject: dovecot mailing list probe message Date: Mon, 30 Mar 2026 06:32:58 +0000 From: [3]dovecot-bounces+a190cb9ae5d94d8fa6e2af68fc964a7aaa13256b(a)dovecot.org To: [4]jaco(a)uls.co.za This is a probe message. You can ignore this message. The [5]dovecot(a)dovecot.org mailing list has received a number of bounces from you, indicating that there may be a problem delivering messages to [6]jaco(a)uls.co.za. A sample is attached below. Please examine this message to make sure there are no problems with your email address. You may want to check with your mail administrator for more help. You don't need to do anything to remain an enabled member of the mailing list. If you have any questions or problems, you can contact the mailing list owner at [7]dovecot-owner(a)dovecot.org References Visible links 1. mailto:dovecot@dovecot.org 2. mailto:dovecot-leave@dovecot.org 3. mailto:dovecot-bounces+a190cb9ae5d94d8fa6e2af68fc964a7aaa13256b@dovecot.org 4. mailto:jaco@uls.co.za 5. mailto:dovecot@dovecot.org 6. mailto:jaco@uls.co.za 7. mailto:dovecot-owner@dovecot.org

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Update to v2.4.3 breaks ldap connection
by markus-dovecot＠doits.de 30 Mar '26

30 Mar '26

Unfortunately the upgrade to v2.4.3 broke the ldap connection. I have configured an ldap connection like this: ``` ldap_uris = ldaps://xxx.com ldap_auth_dn = uid=xxx,ou=general accounts,dc=xxx,dc=com ldap_auth_dn_password = xxx ldap_base = dc=xxx,dc=com passdb ldap { ldap_bind = yes [...] } ``` v2.4.3 cannot connect and says: ``` auth: Error: ldap(ldaps://xxx.com636): Can't connect to server: ldaps://xxx.com ``` Ldap server logs: ``` ACCEPT from IP=[XXX]:45674 (IP=[::]:636) TLS established tls_ssf=256 ssf=256 tls_proto=TLS1.3 tls_cipher=AES-256-GCM closed (connection lost) ``` Downgrade to dovecot v2.4.2 makes it work again. Was there any ldap change in v2.4.3 that required a config change? Using ubuntu 24.04 with the dovecot ppa, now forced version 2.4.2 by using https://repo.dovecot.org/ce-2.4.2/ubuntu/noble

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Dovecot 2.4.3 virtual now broken even more
by sev monster 30 Mar '26

30 Mar '26

As of 2.4.2, Dovecot no longer crashed and broken config vars no longer caused it to error out, so I finally (reluctantly) switched to it over 2.3, though I had to disable/change a few things to get it to work. However, my virtual namespaces were still broken, since the `autosubscribe = yes` option would cause the driver to attempt to create the virtual directories, and fail when they already existed. Turning off autosubscribe meant that the folders were not visible to my users without manually subscribing. With 2.4.3, now the virtual configs that "worked" before now cause Dovecot to error out completely! Yay It seems this commit introduced a "feature" that restricts the virtual driver to the fs list format: https://github.com/dovecot/core/commit/b4a4a32361b8f0e68ef230add6467eddd0ff… But why? Is fs the only format that works? But maildir++ worked in both 2.3 and in previous versions of 2.4. The 2.4.3 docs (still) also recommend switching to maildir++ if desired: https://doc.dovecot.org/2.4.3/core/plugins/virtual.html#virtual-mailbox-plu… In my config, I use maildir for everything. That means in my mailboxes and all my namespaces. But with this change, I must now use fs as my list format for the virtuals. But, I can't do that, because all `list = yes` namespaces in use by a mailbox must use the same list format... So now my previously invisible virtual folders now cause Dovecot to fall over and I have to completely remove the virtual declarations from my config. What am I supposed to do now?

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Executing a sieve-extprograms pipe script as non-root
by Roland Hieber 29 Mar '26

29 Mar '26

Hi, Ultimately I'm trying to call procmail via a `pipe "procmail";` in my Sieve script on Dovecot 2.4.1. I have therefore created the respective wrapper script in /usr/lib/dovecot/sieve-pipe/procmail, but I noted that the script is apparently run as root. With some debug output in the wrapper script, I see: # `id` output uid=0(root) gid=1059(rhi) groups=1059(rhi),116(dovecot) # `pstree -s -u $$` systemd(1)---dovecot(1064)---lmtp(266577,rhi)---procmail(266706,root)---pstree(266711) This Dovecot gets mail delivered via LMTP from another server. 1059 (rhi) is my local user ID on the IMAP server both in /etc/passwd and in /etc/dovecot/users (using auth-passwdfile.conf.ext in 10-auth.conf instead of auth-system.conf.ext), since mail needs to be delivered and chown'ed correctly into Maildirs that should be user-accessible. However I don't understand how the `procmail` wrapper can be run as the root user rights when the LMTP process starting it is running as my own user?!? I'd like to prevent procmail from running as root as far as possible, so for now I've been able to work around this by wrapping the procmail call into an additional `sudo -U $USER` (after determining the user who owns the target maildir), but I'd like to understand the problem a bit further and like to know if this is really how calling sieve-extprograms is supposed to work – I'd have expected that the external scripts are also run as my unprivileged user. I'm running a fairly standard config on Debian stable (dovecot package version 1:2.4.1+dfsg1-6+deb13u2) with only minimal changes by enabling the passwdfile backend and some sieve plugins. Thanks for any insights, - Roland -- Roland Hieber, Pengutronix e.K. | rhi(a)pengutronix.de | Steuerwalder Str. 21 | https://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |

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