- Dovecot-news - dovecot.org

Red Hat Enterprise Linux 8 packages
by Aki Tuomi 08 Sep '25

08 Sep '25

Hi! Due to algorithm limitations, we have signed the RHEL8 packages for 2.4.1 with Dovecot 2.3 signing key. This should make it verifiable on RHEL8. Regards, Aki Tuomi Open-Xchange oy

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Dovecot lifecycle announcement
by Aki Tuomi 12 May '25

12 May '25

We are announcing these Dovecot end-of-life (EOL) decisions: 1. All Dovecot versions before 2.3 are now fully EOL. We will not provide any additional patches, including security issues, for these releases. 2. For Dovecot CE 2.3 we will provide critical security bug fixes. Thus, if you are experiencing a non-security issue with Dovecot, we need you to upgrade into latest 2.4 CE release and reproduce the problem there in order for the team to debug. The Dovecot team will no longer debug non-security related issues for 2.3 releases. If the issue can occur with the latest 2.4 release, please file a bug report and we will take a look! If you are using a 2.3.x version packaged from an Operating System Vendor, please open a bug against them for fixing it. We do not provide patches or bug fixes against these OS Vendor specific releases. Dovecot CE 2.4.x is the current main release, which will continue to receive feature, bug and security patches. We accept bug reports against latest 2.4 version or "main" branch of Dovecot. Packages for Dovecot CE 2.4 can be found at https://repo.dovecot.org. Thank you for using Dovecot! Note: Users with a commercial agreement with Open-Xchange (Dovecot Pro) have a separate extended EOL policy, so this announcement does not apply to them. Regards, Aki Tuomi Open-Xchange oy

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Dovecot v2.4.1 released
by Aki Tuomi 28 Mar '25

28 Mar '25

Hi! We arey happy to release Dovecot v2.4.1! Some IMPORTANT things to notice (still): - We have changed the signing key for 2.4 going forward, releases are signed with EF0882079FD4ED32BF8B23B2A1B09EF84EDC5219, which can be found at https://repo.dovecot.org/DOVECOT-REPO-GPG-2.4 and is signed with the previous key. The old key has been renamed to https://repo.dovecot.org/DOVECOT-REPO-GPG-2.3. - New 2.4 packages **are not** compatible with old 2.3 configuration, please carefully review https://doc.dovecot.org/2.4.1/installation/upgrade/2.3-to-2.4.html before installing the new packages. - We are happy to provide experimental arm64 support in the form of a Docker image. There are now three kinds of images, latest, latest-dev and latest-root. - The latest docker image is now ran rootless, with UID 1000 as vmail. Please take this into consideration when upgrading. The latest-root image still runs as root. Latest 2.3 image can be used with tag 2.3-latest still We won't be sending separate mail about Pigeonhole anymore as we will release one anyways when we release Dovecot, and Pigeonhole versioning has been changed to match Dovecot versioning. Source codes available at - https://www.dovecot.org/releases/2.4/dovecot-2.4.1.tar.gz - https://www.dovecot.org/releases/2.4/dovecot-2.4.1.tar.gz.sig - https://pigeonhole.dovecot.org/releases/2.4/dovecot-pigeonhole-2.4.1.tar.gz - https://pigeonhole.dovecot.org/releases/2.4/dovecot-pigeonhole-2.4.1.tar.gz… Binary packages in https://repo.dovecot.org/ Docker images in https://hub.docker.com/r/dovecot/dovecot Kind regards, Aki Tuomi Open-Xchange oy --- Dovecot Core NEWS ----------------- * auth: Change unix_listener/auth-userdb/group = $SET:default_internal_group This change needs dovecot_config_version=2.4.1. * auth: lua - Remove support for single string result. * imap: Unconditionally advertise SPECIAL-USE capability. * lib-dcrypt: Install dcrypt_openssl.so into dovecot modules directory. * lib-master: For glibc, default MALLOC_MMAP_THRESHOLD_=131072. * lib-storage: Change default mail_cache_fields to: hdr.date hdr.subject hdr.from hdr.sender hdr.reply-to hdr.to hdr.cc hdr.bcc hdr.in-reply-to hdr.message-id date.received size.virtual imap.bodystructure mime.parts hdr.references hdr.importance hdr.x-priority hdr.x-open-xchange-share-url pop3.uidl pop3.order. This change needs dovecot_config_version=2.4.1. * lib-var-expand: Use moduledir instead of pkglibdir for crypt. * lmtp: Change the default lmtp_user_concurrency_limit to 10. This change needs dovecot_config_version=2.4.1. * lmtp: Change the default service_restart_request_count to 1. This change needs dovecot_config_version=2.4.1. + auth: Allow configuring passdb/userdb sql to use auth-workers. + config: Add default group @mailbox_defaults = english. + config: Improve "Unknown setting" error with more details and suggestions. + doveconf: Add -U parameter to ignore unknown settings in config file. + fts-flatcurve: Support lock files in VOLATILEDIR. + imap-acl: Add support for the IMAP LIST-MYRIGHTS capability (RFC 8440). + imap-client: Support ANONYMOUS authentication. + imap: Implement support for the REPLACE capability. - auth: ldap - Passdb fields were ignored with passdb_ldap_bind_userdn=yes. - auth: lua - Fix error result handling in lua passdb/userdb. - auth: oauth2 - When building oauth2 failure reply, memory would leak. - config: local_name handling would work wrong with multiple names and wildcards. - fts-flatcurve: A potential crash could occur when searching virtual mailboxes. Fixes: Panic: file fts-search.c: line 87 (level_scores_add_vuids): assertion failed: (array_count(&vuids_arr) == array_count(&br->scores)) - fts-flatcurve: Maybe queries were done wrong. - fts-flatcurve: Non-selectable mailboxes were not ignored when doing optimize/rescan. - fts-flatcurve: Signal 11 crash could happen with fts rescan. - fts: Fix crash caused by event object lifecycle mishandling. - imap-hibernate: Client counters would get reset on unhibernation, affecting imap_logout_format variables. - imap: Crash would occur with Maildir when trying to send INPROGRESS during mailbox syncing. - ldap: Dovecot could not be compiled without LDAP. - lib-dcrypt: Output stream encryption can cause assert crash if attempting to encrypt over 64 GiB of data with GCM. This is still not supported with GCM, but it fails better. - lib-http: HTTP client context memory usage was increasing. - lib-http: Pipeline corruption could happen after 100 Continue response. - lib-settings: Variable expansion initialization could crash with Panic: file settings.c: line 1560 (settings_var_expand_init_add): assertion failed: (I_MAX(num_tables, num_provs) == num_ctx) - lib-smtp: Pipelining initial SASL response after AUTH was broken. - lib-var-expand: If filter failed, memory leak would occur. - lib-var-expand: Older bison versions did not have error symbol for handling causing unexpected behaviour on the parser on error conditions. - quota: Quota calculations had minor bugs causing small errors. Pigeonhole NEWS --------------- - global: Fix settings handling bugs. Especially %variables weren't working in various settings. - ldap: Pigeonhole could not be built without LDAP.

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Dovecot v2.4.0 released
by Aki Tuomi 24 Jan '25

24 Jan '25

Hi all, after a very long wait we are finally happy to release Dovecot v2.4.0! Some IMPORTANT things to notice: - We have changed the signing key for 2.4 going forward, releases are signed with EF0882079FD4ED32BF8B23B2A1B09EF84EDC5219, which can be found at https://repo.dovecot.org/DOVECOT-REPO-GPG-2.4 and is signed with the previous key. The old key has been renamed to https://repo.dovecot.org/DOVECOT-REPO-GPG-2.3. - New 2.4 packages **are not** compatible with old 2.3 configuration, please carefully review https://doc.dovecot.org/2.4.0/installation/upgrade/2.3-to-2.4.html before installing the new packages. - We are happy to provide experimental arm64 support in the form of a Docker image. - Docker images are now ran rootless, with UID 1000 as vmail using built sources. Please take this into consideration when upgrading. Latest 2.3 image can be used with tag 2.3-latest, if you are not ready for this change. We won't be sending separate mail about Pigeonhole anymore as we will release one anyways when we release Dovecot, and Pigeonhole versioning has been changed to match Dovecot versioning. Source codes available at - https://www.dovecot.org/releases/2.4/dovecot-2.4.0.tar.gz - https://www.dovecot.org/releases/2.4/dovecot-2.4.0.tar.gz.sig - https://pigeonhole.dovecot.org/releases/2.4/dovecot-pigeonhole-2.4.0.tar.gz - https://pigeonhole.dovecot.org/releases/2.4/dovecot-pigeonhole-2.4.0.tar.gz… Binary packages in https://repo.dovecot.org/ Docker images in https://hub.docker.com/r/dovecot/dovecot Kind regards, Aki Tuomi Open-Xchange oy --- Dovecot Core NEWS ----------------- * config: dovecot_config_version must be the first non-comment line in configuration file. * config: dovecot_storage_version must be in the configuration file. * config: Many configuration options have changed so old configuration files do not work without rewrite. See https://doc.dovecot.org/main/installation/upgrade/2.3-to-2.4.html * config: New variable expansion syntax has been introduced, see https://doc.dovecot.org/main/core/settings/variables.html * config: Some default settings have changed. * config: plugin {} section has been removed. * *-login: With ssl=required, connections from login_trusted_networks are now also required to be SSL/TLS encrypted. * acl: Use ACL settings instead of Global ACL Directories. * auth-worker: auth_worker_max_count is replaced with service auth-worker { process_limit }. * auth: Weak password schemes are disabled by default, use auth_allow_weak_schemes to enable them. * auth_debug, mail_debug: Use log_debug filter instead. * config: All sections require a name, for example passdb/userdb: passdb static { password=secret } * db2: Remove Berkeley DB support. * dict-memcached: This is removed, use Redis instead. * director: Feature has been removed. See potential replacement at https://github.com/dovecot/tools/blob/main/director.lua * doveadm: USER environment variable is only supported with --no-userdb-lookup. One of -u, -F or -A must be used otherwise. * doveconf: Option -n is now default when running doveconf. * dsync: Use doveadm sync instead, legacy symlink has been removed. * fs-sis: Feature is now deprecated and has been made read-only. It will be removed in future release. * fts-lucene, fts-squat: These have been removed, use fts-flatcurve or fts-solr instead. * imap-login: IMAP compression is now handled in proxies. * imap_quota: SETQUOTA / quota_set has been removed. * imap_zlib: This plugin is no longer needed, it's always enabled. * imapc: All features are enabled by default, imapc_features can be used to explicitly disable features that are not wanted. * lib-storage: mbox driver is now frozen. * mail_compress: XZ and LZMA algorithm support has been removed. * mailbox-alias: Plugin has been removed. * old_stats, auth_stats: These have been removed. * openssl: Minimum supported version of OpenSSL is now 1.1.1. * openssl: Add support for OpenSSL 3.x * quota-dict, quota-dirsize: These have been removed, use quota-count instead. You can use quota_clone to copy quota usage to some database. * replicator: Feature has been removed. Use NFS or some other shared filesystem instead, or run doveadm sync in crontab. * stats: The bytes_in and bytes_out field in several events have been renamed as net_in_bytes and net_out_bytes. * zlib: Renamed to mail_compress plugin. + Experimental SMTPUTF8 and IMAP UTF8=ACCEPT support has been added. Needs --enable-experimental-mail-utf8 configure option and mail_utf8_extensions=yes setting. + Long running mail commands can be aborted with Ctrl-C / doveadm kick. + auth: LDAP driver now supports multi-value attributes. + auth: Add support for SCRAM-SHA-1-PLUS and SCRAM-SHA-256-PLUS. + auth: Add support for TLS channel binding. + auth: Support sending JA3 hash to policy server. + configure: Detect latest Lua version. + *-login: Support for TLS Server Name has been improved to allow pre-login settings. For example capabilities to be changed based on TLS Server Name. + *-login: Support for TLS ALPN has been added, connections with mismatching application are now refused. Missing ALPN is accepted. + fts-flatcurve: New Xapian based FTS plugin has been added. + imap: Support for INPROGRESS untagged messages as per RFC 9585. + lib-lua: Expose Dovecot DNS client. + lib-lua: Expose Dovecot HTTP client. + lib-sasl: Support SCRAM-SHA mechanisms. + lmtp: SNI support has been added which allows settings to be applied based on TLS Server Name. + sqlite: Support WAL mode. + stats: Submetric name size has been increased. + submission: Add submission_add_received_header setting to protect sender identity by suppressing the Received: header. - Many bugs have been fixed. Pigeonhole NEWS --------------- * Change configuration syntax to match new Dovecot configuration syntax. * vacation: Reduce default days to 60 from infinity * vacation: vacation_max_period=0 is now an error. * Version has been changed to match Dovecot version. + Added i;unicode-casecmp comparator. - Lots of bugs have been fixed.

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CVE-2024-23184: Having a large number of address headers (From, To, Cc, Bcc, etc.) becomes excessively CPU intensive
by Aki Tuomi 14 Aug '24

14 Aug '24

Affected product: Dovecot IMAP Server Internal reference: DOV-6464 Vulnerability type: CWE-770 (Allocation of Resources Without Limits or Throttling) Vulnerable version: 2.2, 2.3 Vulnerable component: lib-mail Report confidence: Confirmed Solution status: Fixed in 2.3.21.1 Researcher credits: Vendor internal discovery Vendor notification: 2024-01-30 CVE reference: CVE-2024-23184 CVSS: 5.0 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N) Vulnerability Details: Having a large number of address headers (From, To, Cc, Bcc, etc.) becomes excessively CPU intensive. With 100k header lines CPU usage is already 12 seconds, and in a production environment we observed 500k header lines taking 18 minutes to parse. Since this can be triggered by external actors sending emails to a victim, this is a security issue. The main problem is that each header line's address is added to the end of a linked list. This is done by walking the whole linked list, which becomes more inefficient the more addresses there are. Workaround: One can implement restrictions on address headers on MTA component preceding Dovecot. Fix: Install non-vulnerable version of Dovecot. Patch can be found at https://github.com/dovecot/core/compare/8e4c42d%5E...1481c04.patch

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CVE-2024-23185: Very large headers can cause resource exhaustion when parsing message
by Aki Tuomi 14 Aug '24

14 Aug '24

Affected product: Dovecot IMAP Server Internal reference: DOV-6601 Vulnerability type: CWE-770 (Allocation of Resources Without Limits or Throttling) Vulnerable version: 2.2, 2.3 Vulnerable component: lib-mail Report confidence: Confirmed Solution status: Fixed in 2.3.21.1 Researcher credits: Vendor internal discovery Vendor notification: 2024-01-31 CVE reference: CVE-2024-23185 CVSS: 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) Vulnerability Details: Very large headers can cause resource exhaustion when parsing message. The message-parser normally reads reasonably sized chunks of the message. However, when it feeds them to message-header-parser, it starts building up "full_value" buffer out of the smaller chunks. The full_value buffer has no size limit, so large headers can cause large memory usage. It doesn't matter whether it's a single long header line, or a single header split into multiple lines. This bug exists in all Dovecot versions. Incoming mails typically have some size limits set by MTA, so even largest possible header size may still fit into Dovecot's vsz_limit. So attackers probably can't DoS a victim user this way. A user could APPEND larger mails though, allowing them to DoS themselves (although maybe cause some memory issues for the backend in general). Workaround: One can implement restrictions on headers on MTA component preceding Dovecot. Fix: Install non-vulnerable version of Dovecot. Patch can be found at https://github.com/dovecot/core/compare/f020e13%5E...ce88c33.patch

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Pigeonhole v0.5.21.1 released
by Aki Tuomi 14 Aug '24

14 Aug '24

Hi all, we are releasing new version of Pigeonhole. https://pigeonhole.dovecot.org/releases/2.3/dovecot-2.3-pigeonhole-0.5.21.1… https://pigeonhole.dovecot.org/releases/2.3/dovecot-2.3-pigeonhole-0.5.21.1… Binary packages in https://repo.dovecot.org/ Docker images in https://hub.docker.com/r/dovecot/dovecot Kind regards, Aki Tuomi Open-Xchange oy --- - sieve: When saving to local storage failed after a successful action in sieve (e.g. redirect, vacation), the mail was reported as successfully delivered, although it was lost locally.

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Dovecot v2.3.21.1 released
by Aki Tuomi 14 Aug '24

14 Aug '24

Hi all, we are releasing a CVE patch release 2.3.21.1. https://dovecot.org/releases/2.3/dovecot-2.3.21.1.tar.gz https://dovecot.org/releases/2.3/dovecot-2.3.21.1.tar.gz.sig Binary packages in https://repo.dovecot.org/ Docker images in https://hub.docker.com/r/dovecot/dovecot Kind regards, Aki Tuomi Open-Xchange oy --- - CVE-2024-23184: A large number of address headers in email resulted in excessive CPU usage. - CVE-2024-23185: Abnormally large email headers are now truncated or discarded, with a limit of 10MB on a single header and 50MB for all the headers of all the parts of an email. - oauth2: Dovecot would send client_id and client_secret as POST parameters to introspection server. These need to be optionally in Basic auth instead as required by OIDC specification. - oauth2: JWT key type check was too strict. - oauth2: JWT token audience was not validated against client_id as required by OIDC specification. - oauth2: XOAUTH2 and OAUTHBEARER mechanisms were not giving out protocol specific error message on all errors. This broke OIDC discovery. - oauth2: JWT aud validation was not performed if aud was missing from token, but was configured on Dovecot.

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Pigeonhole v0.5.21 released
by Aki Tuomi 15 Sep '23

15 Sep '23

Hi all! We are pleased to release v0.5.21 of Pigeonhole. https://pigeonhole.dovecot.org/releases/2.3/dovecot-2.3-pigeonhole-0.5.21.t… https://pigeonhole.dovecot.org/releases/2.3/dovecot-2.3-pigeonhole-0.5.21.t… Binary packages in https://repo.dovecot.org/ Docker images in https://hub.docker.com/r/dovecot/dovecot Regards, Aki Tuomi Open-Xchange oy --- - sieve: Using the deleteheader action on a message with a broken/invalid header can cause the Sieve interpreter to crash with an assert panic. This can happen e.g. when the message is missing the empty EOH line between the headers and the body of the message. Fixes: Panic: file edit-mail.c: line 820 (edit_mail_headers_parse): assertion failed: (body_offset > 0). - sieve: Pigeonhole added an extra Message-ID header during mail forwarding when the existing one was invalid. Now it adds the Message-ID only if it is entirely missing. Existing Message-ID(s) are left unchanged.

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Dovecot v2.3.21 released
by Aki Tuomi 15 Sep '23

15 Sep '23

Hi all! We are pleased to release v2.3.21 of Dovecot. https://dovecot.org/releases/2.3/dovecot-2.3.21.tar.gz https://dovecot.org/releases/2.3/dovecot-2.3.21.tar.gz.sig Binary packages in https://repo.dovecot.org/ Docker images in https://hub.docker.com/r/dovecot/dovecot Regards, Aki Tuomi Open-Xchange oy --- * lib-oauth2: Allow JWT tokens to be validated with missing typ field. The typ field is left out by some key issuers to conserve space, notably kubernetes. Now missing typ is tolerated, but if present, it still must be "jwt". + auth: Auth passdb and userdb reply can contain "event_<name>=value" which will be added to login event and mail user event respectively. + lib-master: Set process title during various initialization stages to clearly describe what the process is waiting on. + lib-storage: The mail_temp_scan_interval is now fuzzed incrementing it by 0..30% based on username's hash to reduce the chance of load spikes . + lib-storage: The temp file scan has been moved from the open of the mailbox to the close, to reduce the latency perceived by users. + stats: If metric has fields specified, all these fields are exported as counters to prometheus exposition. See https://doc.dovecot.org/configuration_manual/stats/openmetrics/. - *-login: Processes might have crashed when a SSL connection disconnect s uncleanly. - acl: When plugin was loaded \HasChildren and \HasNoChildren flags were calculated incorrectly for mailboxes containing '*' and '%' in their names. - auth: Crash occured if a connection to PostgreSQL database server failed during startup. - auth: Logins with invalid passwords (e.g. unknown scheme) in passdb were failing with "password mismatch" instead of "internal error". - auth: XOAUTH2 and OAUTHBEARER mechanisms were not giving out protocol specific error message on all errors. This especially broke OIDC discovery. - dbox: When last_temp_file_scan header wasn't set (especially after dsync migration), the next mailbox open always triggers the temp file scan. This could have caused a load spike after migrations. Fixed by using the mailbox directory's atime when the header isn't set, which usually moves the scan time into the future. - dict-redis: A crash would occur on transaction rollback. - dsync: Infinite loop causing out of memory would occur when handling mailbox deletion from remote end and hierarchy separators would differ. - dsync: Incremental dsync failed for folder names ending with '%', unless BROKENCHAR was set. Also folder names with '%' elsewhere in them caused each incremental dsync to unnecessarily rename the folder to a temporary name and back. v2.3.19 regression. - imap-hibernate: If an IMAP client unhibernation timed out with "(version received)", the unhibernation could still have successfully finished later on and continued working normally. This was rather confusing, because imap-hibernate already logged that the client got disconnected. Avoid this by forcing the connection to shutdown on unhibernation timeout. - imapc: Crashed when a folder mapped through the virtual plugin disappears from the storage. - imapc: EXPUNGE, EXISTS or FETCH replies from a server for a previously selected mailbox could have been processed as if they belonged to the new mailbox currently being selected. This could have caused warnings. - lib-http: Dovecot HTTP server (doveadm, stats/openmetrics) may have disconnected HTTP clients before the response is fully sent. This happened only on busy servers where kernel's socket buffers were rather full. - lib-http: Fixed a potential crash on http-server if a client disconnected early. v2.3.18 regression. - lib-index: Index file corruption could have caused a crash. Fixes: Panic: file mail-transaction-log-view.c: line 165 (mail_transaction_log_view_set): assertion failed: (min_file_seq <= max_file_seq). - lib-index: Purging an existing >1GB cache file can crash. Now cache files still above 1GB after purging are removed. Fixes: Panic: file mail-index-util.c: line 10 (mail_index_uint32_to_offset): assertion failed: (offset < 0x40000000) - lib-lua: A HTTP client could not resolve DNS names in mail processes, because it expected "the dns-client" socket to exist in the current directory. - lib-oauth2: Dovecot would send client_id and client_secret as POST parameters to the introspection server. These need to be optionally in Basic auth instead. - lib-oauth2: JWT aud validation was not performed if aud was missing from a token, but was configured on Dovecot. - lib-oauth2: JWT key type check was too strict. - lib-oauth2: JWT token audience was not validated against client_id as required by the specification. - lib-ssl-iostream: Using the ssl_require_crl=yes setting may have caused CRL check failures for outgoing SSL/TLS connections, although it was supposed to affect checking CRLs only for client-side SSL certificates. v2.3.17 regression. - lib-sql: MySQL driver leaked memory when connection failed. - lib-storage: Various fixes when running into out of disk space. - master: Service idle_kill setting didn't work properly on busy servers. It was very unlikely that any process was idling long enough to become killed. Also the idle_kill handling code was using quite a lot of CPU on the master process when there were a lot of processes (e.g. imap). The new behavior is to track the lowest number of idling processes every idle_kill time interval and then kill that many idling processes. - mdbox: Temp file scan was done for always empty directories. - mdbox: The fdatasync() call was done in wrong parent directory when writing mails. Also on a failure it crashed instead of logging an error. - notify_status: The plugin crashes if any user initialization fails. - pop3: Sending command with the ':' character caused an assert-crash. v2.3.18 regression. Fixes: Panic: event_reason_code_prefix(): name has ':' - stats: Fix panic when a nonexistent event exporter was referenced while adding a new metric dynamically via doveadm stats add. This produces a proper error now. - stats: If process exported a lot of events and then exited, some of the last events may have become lost. - stats: Invalid Prometheus label names were created with specific histogram group_by configurations. Prometheus rejected these labels. - welcome: The plugin didn't execute in some situations that created INBOX but didn't open it, e.g. if GETMETADATA was used before the INBOX was opened.

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