- dovecot - dovecot.org

Doveadm and iterate query
by Bogusław Juza 18 Jul '26

18 Jul '26

Hi! I have a problem with Dovecot on Debian 13: Dovecot 2.4.1, Debian Trixie > doveadm mailbox path -A INBOX >/dev/null doveadm(email@domain): Error: auth-master: userdb list: User listing returned failure doveadm: Error: cmd mailbox path: Failed to iterate through some users userdb sql { iterate_query = SELECT `email` AS `user` FROM `users` } In syslog file: dovecot: auth: Error: auth-worker: Aborted LIST request for *: Shutting down I have over 30k users in sql DB, doveadm with -A option is dying few second after start with this error, printing about 10% of users. I need much more time (FE command "doveadm expunge -A mailbox Spam savedbefore 3w" could run over 30 minutes). What I'm doing wrong? Bogusław Juza

3 2

Strange characters in log file
by Doug Hardie 18 Jul '26

18 Jul '26

I am occasionally finding some strange characters in the log file. I have captured on entry that vi cannot handle. It simply won't go past this record. I suspect the issue is around 0347 in the record below. Any ideas how to prevent this from happening as it makes it difficult to find specific records in the log. vi is unable to delete the line with this issue. mail# head -1 imaplog.test | od -t x1c 0000000 4a 75 6c 20 31 37 20 30 32 3a 33 34 3a 35 35 20 J u l 1 7 0 2 : 3 4 : 5 5 0000020 6d 61 69 6c 20 64 6f 76 65 63 6f 74 5b 35 32 39 m a i l d o v e c o t [ 5 2 9 0000040 30 5d 3a 20 69 6d 61 70 28 64 6f 75 67 29 5b 31 0 ] : i m a p ( d o u g ) [ 1 0000060 30 2e 30 2e 31 2e 32 33 32 5d 3c 4e 74 79 78 52 0 . 0 . 1 . 2 3 2 ] < N t y x R 0000100 4d 74 57 4e 64 38 4b 41 41 48 6f 3e 3a 20 64 65 M t W N d 8 K A A H o > : d e 0000120 6c 65 74 65 3a 20 62 6f 78 3d 44 65 6c 65 74 65 l e t e : b o x = D e l e t e 0000140 64 20 4d 65 73 73 61 67 65 73 2c 20 75 69 64 3d d M e s s a g e s , u i d = 0000160 35 38 32 32 31 33 2c 20 6d 73 67 69 64 3d 3c 39 5 8 2 2 1 3 , m s g i d = < 9 0000200 31 30 35 30 36 39 31 2e 31 34 37 36 39 34 36 2e 1 0 5 0 6 9 1 . 1 4 7 6 9 4 6 . 0000220 31 37 38 33 35 38 37 39 33 35 37 36 36 40 6d 61 1 7 8 3 5 8 7 9 3 5 7 6 6 @ m a 0000240 72 6b 65 74 6f 2d 70 6c 61 74 66 6f 72 6d 2d 2d r k e t o - p l a t f o r m - - 0000260 65 6d 61 69 6c 2d 73 65 6e 64 65 72 2d 70 72 6f e m a i l - s e n d e r - p r o 0000300 64 2d 62 61 74 63 68 2d 63 6c 75 2e 2e 2e 2c 20 d - b a t c h - c l u . . . , 0000320 73 69 7a 65 3d 35 35 39 39 30 2c 20 66 72 6f 6d s i z e = 5 5 9 9 0 , f r o m 0000340 3d 57 4f 52 4c 44 e2 4d 2d 5e 40 4d 2d 5e 59 73 = W O R L D 342 M - ^ @ M - ^ Y s 0000360 20 54 69 6d 20 4c 61 6d 65 72 20 3c 65 64 69 74 T i m L a m e r < e d i t 0000400 6f 72 40 77 6e 67 2e 6f 72 67 3e 0a o r @ w n g . o r g > \n 0000414 -- Doug I am occasionally finding some strange characters in the log file. I have captured on entry that vi cannot handle. It simply won't go past this record. I suspect the issue is around 0347 in the record below. Any ideas how to prevent this from happening as it makes it difficult to find specific records in the log. vi is unable to delete the line with this issue. mail# head -1 imaplog.test | od -t x1c 0000000 4a 75 6c 20 31 37 20 30 32 3a 33 34 3a 35 35 20 J u l 1 7 0 2 : 3 4 : 5 5 0000020 6d 61 69 6c 20 64 6f 76 65 63 6f 74 5b 35 32 39 m a i l d o v e c o t [ 5 2 9 0000040 30 5d 3a 20 69 6d 61 70 28 64 6f 75 67 29 5b 31 0 ] : i m a p ( d o u g ) [ 1 0000060 30 2e 30 2e 31 2e 32 33 32 5d 3c 4e 74 79 78 52 0 . 0 . 1 . 2 3 2 ] < N t y x R 0000100 4d 74 57 4e 64 38 4b 41 41 48 6f 3e 3a 20 64 65 M t W N d 8 K A A H o > : d e 0000120 6c 65 74 65 3a 20 62 6f 78 3d 44 65 6c 65 74 65 l e t e : b o x = D e l e t e 0000140 64 20 4d 65 73 73 61 67 65 73 2c 20 75 69 64 3d d M e s s a g e s , u i d = 0000160 35 38 32 32 31 33 2c 20 6d 73 67 69 64 3d 3c 39 5 8 2 2 1 3 , m s g i d = < 9 0000200 31 30 35 30 36 39 31 2e 31 34 37 36 39 34 36 2e 1 0 5 0 6 9 1 . 1 4 7 6 9 4 6 . 0000220 31 37 38 33 35 38 37 39 33 35 37 36 36 40 6d 61 1 7 8 3 5 8 7 9 3 5 7 6 6 @ m a 0000240 72 6b 65 74 6f 2d 70 6c 61 74 66 6f 72 6d 2d 2d r k e t o - p l a t f o r m - - 0000260 65 6d 61 69 6c 2d 73 65 6e 64 65 72 2d 70 72 6f e m a i l - s e n d e r - p r o 0000300 64 2d 62 61 74 63 68 2d 63 6c 75 2e 2e 2e 2c 20 d - b a t c h - c l u . . . , 0000320 73 69 7a 65 3d 35 35 39 39 30 2c 20 66 72 6f 6d s i z e = 5 5 9 9 0 , f r o m 0000340 3d 57 4f 52 4c 44 e2 4d 2d 5e 40 4d 2d 5e 59 73 = W O R L D 342 M - ^ @ M - ^ Y s 0000360 20 54 69 6d 20 4c 61 6d 65 72 20 3c 65 64 69 74 T i m L a m e r < e d i t 0000400 6f 72 40 77 6e 67 2e 6f 72 67 3e 0a o r @ w n g . o r g > \n 0000414 -- Doug

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How to use sieve_env_ variables in 2.4.4?
by inaugurator＠ya.ru 16 Jul '26

16 Jul '26

Hi Dear Devs! In the previous version 2.3.x I used variables with the **sieve_env_** prefix to access them later in Sieve scripts, for example `sieve_env_hello = hello` changed to `"${env.vnd.dovecot.config.hello}"`. But now I am getting an error ``` doveconf: Fatal: Error in configuration file /etc/dovecot/dovecot.conf line 11: sieve_env_hello: Unknown setting: sieve_env_hello ``` Thank you in advance!

2 2

dsync does not like sieve
by Stéphane Veyret 14 Jul '26

14 Jul '26

Hi, I’m using Dovecot for many years. My installation is configured to manage spam using sieve. In the same time, I have a backup server, connecting to the main server every night in order to backup emails (note that the main server is not pushing its data, but the backup server is pulling them). Dovecot v2.4 made me re-write the configuration files, so maybe I missed something, but since then, I cannot make both these service work in the same time. With my current configuration, the backup server is terminating in error with the following logs: dsync-remote(example(a)example.com)<HbkSGoKQG2o8+gEAGKlOPA>: Error: brain S: Exporting mailbox INBOX failed: Mailbox attribute iteration failed: Internal error occurred. Refer to server log for more information. [2026-05-31 03:36:03] (and there are no more logs anywhere). Because this message <https://dovecot.org/mailman3/archives/list/dovecot@dovecot.org/thread/MGCGR…> was suggesting there could be a problem with sieve, I tried to modify the configuration. And indeed, when changing sieve configuration, the backup is working again. But then, my spam filter isn’t anymore. Here are the relevant parts of the configuration for managing sieve. Can someone help me saying what could be wrong? protocols { sieve = yes imap = yes lmtp = yes } sieve_extensions { fileinto = yes reject = yes envelope = yes encoded-character = yes vacation = yes subaddress = yes comparator-i;ascii-numeric = yes relational = yes regex = yes imap4flags = yes copy = yes include = yes body = yes variables = yes enotify = yes environment = yes mailbox = yes date = yes index = yes ihave = yes duplicate = yes mime = yes foreverypart = yes extracttext = yes vnd.dovecot.pipe = yes vnd.dovecot.environment = yes } sieve_pipe_bin_dir = /etc/dovecot/sieve sieve_pipe_socket_dir = sieve-pipe sieve_plugins { sieve_imapsieve = yes sieve_extprograms = yes } service managesieve-login { inet_listener sieve { port = 4190 } } sieve_script personal { } sieve_script default { path = /etc/dovecot/sieve/spam.sieve } protocol imap { mail_plugins { acl = yes quota = yes imap_acl = yes imap_quota = yes imap_sieve = yes } } protocol lmtp { mail_plugins { acl = yes quota = yes sieve = yes } } namespace user { inbox = yes prefix = separator = / type = private mailbox * { sieve_script reportspam { cause = flag path = /etc/dovecot/sieve/report-spam.sieve type = before } } } Thank you. Stéphane -- Bien cordialement, / Plej kore, Stéphane Veyret Hi, I'm using Dovecot for many years. My installation is configured to manage spam using sieve. In the same time, I have a backup server, connecting to the main server every night in order to backup emails (note that the main server is not pushing its data, but the backup server is pulling them). Dovecot v2.4 made me re-write the configuration files, so maybe I missed something, but since then, I cannot make both these service work in the same time. With my current configuration, the backup server is terminating in error with the following logs: dsync-remote([1]example(a)example.com)<HbkSGoKQG2o8+gEAGKlOPA>: Error: brain S: Exporting mailbox INBOX failed: Mailbox attribute iteration failed: Internal error occurred. Refer to server log for more information. [2026-05-31 03:36:03] (and there are no more logs anywhere). Because [2]this message was suggesting there could be a problem with sieve, I tried to modify the configuration. And indeed, when changing sieve configuration, the backup is working again. But then, my spam filter isn't anymore. Here are the relevant parts of the configuration for managing sieve. Can someone help me saying what could be wrong? protocols { sieve = yes imap = yes lmtp = yes } sieve_extensions { fileinto = yes reject = yes envelope = yes encoded-character = yes vacation = yes subaddress = yes comparator-i;ascii-numeric = yes relational = yes regex = yes imap4flags = yes copy = yes include = yes body = yes variables = yes enotify = yes environment = yes mailbox = yes date = yes index = yes ihave = yes duplicate = yes mime = yes foreverypart = yes extracttext = yes vnd.dovecot.pipe = yes vnd.dovecot.environment = yes } sieve_pipe_bin_dir = /etc/dovecot/sieve sieve_pipe_socket_dir = sieve-pipe sieve_plugins { sieve_imapsieve = yes sieve_extprograms = yes } service managesieve-login { inet_listener sieve { port = 4190 } } sieve_script personal { } sieve_script default { path = /etc/dovecot/sieve/spam.sieve } protocol imap { mail_plugins { acl = yes quota = yes imap_acl = yes imap_quota = yes imap_sieve = yes } } protocol lmtp { mail_plugins { acl = yes quota = yes sieve = yes } } namespace user { inbox = yes prefix = separator = / type = private mailbox * { sieve_script reportspam { cause = flag path = /etc/dovecot/sieve/report-spam.sieve type = before } } } Thank you. Stephane -- Bien cordialement, / Plej kore, Stephane Veyret References Visible links 1. mailto:example@example.com 2. https://dovecot.org/mailman3/archives/list/dovecot@dovecot.org/thread/MGCGR…

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imap-sieve, question concerning "sieve_user_email" and variables, migration from 2.3 to 2.4
by Claus-Justus Heine 14 Jul '26

14 Jul '26

Hi there, I have a question concerning the configuration setting sieve_user_email In a v2.3 setup I had it set to sieve_user_email = %Ln(a)some.concrete.domain Now I am trying to migrate to v2.4 and thought the direct translation from the old variable expansion scheme to the new scheme deployed in v2.4 would be sieve_user_email = %{user|username|lower}(a)some.concrete.domain However, this does not work. Testing the documentation yields the following error: # dovecot -n -c dovecot.conf > /dev/null doveconf: Error: sieve: sieve settings: Failed to parse configuration: Failed to expand sieve_user_email setting variables: Unknown variable 'user' doveconf: Fatal: Error in configuration file dovecot.conf: Failed to initialize Sieve Setting "sieve_user_email" to something without variable expansion or just commenting it out yields a configuration which is accepted by "dovecot -n". Now I wonder: a) v2.3 did not complain. But perhaps just because it was using "%Ln" literally? b) In case it did work in v2.3, should it work in v2.4 also? And if so: what would be the correct syntax / variable names? c) Under which circumstances is this setting "sieve_user_email" used? The documentation states: https://doc.dovecot.org/main/core/summaries/settings.html#sieve_user_email > The primary e-mail address for the user. > > This is used as a default when no other appropriate address is available for sending messages. > > If this setting is not configured, either the postmaster or null <> address is used as a sender, depending on the action involved. > > This setting is important when there is no message envelope to extract addresses from, such as when the script is executed in IMAP. I thought that then it would make sense to use something which depends on the login-name of the IMAP-user? Or was this "sieve_user_email" intended to hold just one static email like "my_global_catch_all(a)some.concrete.domain"? Kind thanks for clarification, best regards Claus -- Claus-Justus Heine himself(a)claus-justus-heine.de http://www.claus-justus-heine.de/ Schatzmeister der Camerata Academica Freiburg e.V. --- www.cafev.de

2 3

NFC normalization rename errors after 2.3 to 2.4 upgrade (mdbox)
by Jan Münnich 14 Jul '26

14 Jul '26

Hi, We just upgraded from 2.3 to 2.4.3 and are now getting errors like this for any mailbox with German umlauts in the name: "Error: Failed to rename mailbox 'Anträge' for NFC normalization: Mailbox doesn't exist: Anträge" The mailboxes work fine otherwise, doveadm mailbox status shows them with correct message counts. The errors show up on IMAP access but don't seem to break anything. We're using mdbox. On disk the directory is stored as mUTF-7: Antr&AOQ-ge doveadm mailbox list gives back the name with c3 a4 for the ä, which is already NFC. We double-checked with python3 unicodedata and it confirms the name is NFC. So it seems like dovecot is trying to rename something that doesn't need renaming, and then failing. Is there a way to turn off this automatic rename? Or is this a known issue with mdbox and mUTF-7 directory names? Any help would be appreciated to find out if this is a bug or a configuration issue on our side! Thanks, Jan

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crash in sieve-filter with 2.4.4
by Noah Meyerhans 13 Jul '26

13 Jul '26

Forwarded from https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1139275 A certain poison pill message seems to crash sieve-filter. A reproducer script, email message, and sieve script are at https://salsa.debian.org/noahm/dovecot/-/tree/sieve-crash/debian/tests/siev… The problem is not reproducible with 2.4.1, so it seems to be a regression introduced since then. Coredump details follow: root@dovecot-test:/home/noahm/dovecot# coredumpctl info | cat PID: 110911 (sieve-filter) TID: 110911 (sieve-filter) UID: 65534 (nobody) GID: 65534 (nogroup) Signal: 6 (ABRT) Timestamp: Mon 2026-06-08 19:16:37 UTC (29s ago) Command Line: sieve-filter -u dep8 -e -W -D -C -v /srv/dovecot-dep8/test.sieve INBOX Executable: /usr/bin/sieve-filter Control Group: /user.slice/user-1000.slice/session-5.scope Unit: session-5.scope Slice: user-1000.slice Session: 5 Owner UID: 1000 (noahm) Boot ID: 46469969e01043559d913ef8ab625856 Machine ID: a497a098bd094c1c8f7c8ed02aa21853 Hostname: dovecot-test Storage: /var/lib/systemd/coredump/core.sieve-filter.65534.46469969e01043559d913ef8ab625856.110911.1780946197000000.zst (present) Size on Disk: 253.5K Message: Process 110911 (sieve-filter) of user 65534 dumped core. Module libgcc_s.so.1 from deb gcc-16-16.1.0-1.amd64 Module libstdc++.so.6 from deb gcc-16-16.1.0-1.amd64 Stack trace of thread 110911: #0 0x00007fe06b09fcfc n/a (libc.so.6 + 0x97cfc) #1 0x00007fe06b048d02 raise (libc.so.6 + 0x40d02) #2 0x00007fe06b0304b2 abort (libc.so.6 + 0x284b2) #3 0x00007fe06b26ed45 n/a (libdovecot.so.0 + 0x6ed45) #4 0x00007fe06b357597 default_fatal_handler (libdovecot.so.0 + 0x157597) #5 0x00007fe06b26ec72 i_panic (libdovecot.so.0 + 0x6ec72) #6 0x00007fe06b273b90 n/a (libdovecot.so.0 + 0x73b90) #7 0x00007fe06b3498fb n/a (libdovecot.so.0 + 0x1498fb) #8 0x00007fe06b34a784 n/a (libdovecot.so.0 + 0x14a784) #9 0x00007fe06b34a93b buffer_append (libdovecot.so.0 + 0x14a93b) #10 0x00007fe06b344cc6 dregex_code_match_groups (libdovecot.so.0 + 0x144cc6) #11 0x00007fe06b806a27 n/a (libdovecot-sieve.so.0 + 0x6da27) #12 0x00007fe06b806cd0 n/a (libdovecot-sieve.so.0 + 0x6dcd0) #13 0x00007fe06b7ee411 sieve_match_value (libdovecot-sieve.so.0 + 0x55411) #14 0x00007fe06b7ee711 sieve_match (libdovecot-sieve.so.0 + 0x55711) #15 0x00007fe06b7f5862 n/a (libdovecot-sieve.so.0 + 0x5c862) #16 0x00007fe06b7eccde sieve_interpreter_continue (libdovecot-sieve.so.0 + 0x53cde) #17 0x00007fe06b7fbfbe sieve_execute (libdovecot-sieve.so.0 + 0x62fbe) #18 0x00005638c0022fcf main (sieve-filter + 0x3fcf) #19 0x00007fe06b031f77 n/a (libc.so.6 + 0x29f77) #20 0x00007fe06b032027 __libc_start_main (libc.so.6 + 0x2a027) #21 0x00005638c0023791 _start (sieve-filter + 0x4791) ELF object binary architecture: AMD x86-64

2 1

sieve-test (Pigeonhole) on Ubuntu: PCRE support and address test restrictions on Return-Path
by michael.merz＠wtnet.de 11 Jul '26

11 Jul '26

Hello, I've been evaluating sieve-test (Pigeonhole, dovecot-sieve package, version 2.3.21, as shipped with Ubuntu 24.04 LTS) as an offline testing tool for a personal Sieve ruleset that currently runs on a Cyrus IMAPd/CMU Sieve 3.0 backend. I'd like to ask for some clarification on two points, in case I'm missing a configuration option. 1) PCRE support My ruleset makes extensive use of the `(?i)` inline case-insensitivity flag within :regex tests, which is valid under PCRE (as used by Cyrus). When running sieve-test, I get: error: invalid regular expression '(?i)...' for regex match: invalid preceding regular expression. Checking `dovecot --build-options` shows no PCRE entry, which suggests the Ubuntu-packaged binary was compiled without --with-pcre and falls back to POSIX extended regex. Question: Is PCRE support in Pigeonhole's regex extension purely a compile-time decision (i.e. something that would need to be addressed at the distribution packaging level, not via runtime configuration), or is there a runtime way to enable PCRE matching that I might have missed (e.g. via -o, sieve_extensions, or similar)? 2) Return-Path in the `address` test Several of my rules use: address :domain :is "return-path" "..." Cyrus accepts this. Pigeonhole's sieve-test rejects it with: error: specified header 'return-path' is not allowed for the address test. I understand this is likely an RFC 5228 strictness difference (Cyrus being more permissive than the RFC requires). Is there a recommended alternative within Sieve itself to achieve the same effect (testing the address portion of Return-Path) while staying within what Pigeonhole accepts - e.g. via the `header` test combined with some address-parsing approach, or via the envelope test instead? For context: I'm not running a Dovecot mail server myself. I'm using sieve-test purely as an offline syntax/behaviour verification tool before deploying ruleset changes to a separate Cyrus-based production system. I understand this is a bit of an unusual use case, so any guidance on whether Pigeonhole is well suited for this kind of cross-implementation testing at all would also be appreciated. Thank you for your time and for maintaining Pigeonhole. Best regards, Michael Merz Hello, I've been evaluating sieve-test (Pigeonhole, dovecot-sieve package, version 2.3.21, as shipped with Ubuntu 24.04 LTS) as an offline testing tool for a personal Sieve ruleset that currently runs on a Cyrus IMAPd/CMU Sieve 3.0 backend. I'd like to ask for some clarification on two points, in case I'm missing a configuration option. 1) PCRE support My ruleset makes extensive use of the `(?i)` inline case-insensitivity flag within :regex tests, which is valid under PCRE (as used by Cyrus). When running sieve-test, I get: error: invalid regular expression '(?i)...' for regex match: invalid preceding regular expression. Checking `dovecot --build-options` shows no PCRE entry, which suggests the Ubuntu-packaged binary was compiled without --with-pcre and falls back to POSIX extended regex. Question: Is PCRE support in Pigeonhole's regex extension purely a compile-time decision (i.e. something that would need to be addressed at the distribution packaging level, not via runtime configuration), or is there a runtime way to enable PCRE matching that I might have missed (e.g. via -o, sieve_extensions, or similar)? 2) Return-Path in the `address` test Several of my rules use: address :domain :is "return-path" "..." Cyrus accepts this. Pigeonhole's sieve-test rejects it with: error: specified header 'return-path' is not allowed for the address test. I understand this is likely an RFC 5228 strictness difference (Cyrus being more permissive than the RFC requires). Is there a recommended alternative within Sieve itself to achieve the same effect (testing the address portion of Return-Path) while staying within what Pigeonhole accepts -- e.g. via the `header` test combined with some address-parsing approach, or via the envelope test instead? For context: I'm not running a Dovecot mail server myself. I'm using sieve-test purely as an offline syntax/behaviour verification tool before deploying ruleset changes to a separate Cyrus-based production system. I understand this is a bit of an unusual use case, so any guidance on whether Pigeonhole is well suited for this kind of cross-implementation testing at all would also be appreciated. Thank you for your time and for maintaining Pigeonhole. Best regards, Michael Merz

4 13

Client sent invalid input for CATEGORY
by Mail Operations 09 Jul '26

09 Jul '26

Hello list We are running a dovecot 2.4 instance and the following errors start to pop up after a listener is configured to scrape metrics with Prometheus: ... dovecot[2090309]: stats: Error: conn unix:stats (pid=2090333,uid=108): Client sent invalid input for CATEGORY: Category parent 'ssl' changed to 'ssl' (input: CATEGORY ssl-client ssl) Stats listener config: service stats { inet_listener http { port = 9090 ssl = yes } } So far I failed to reliably trigger the error messages and it looks like they appear randomly. Besides the logged errors, everything seems to work correctly. Could this be a possible bug, or configuration error? Kind regards, Patrik

2 2

doveadm backup / purge problems since migration from 2.3 to 2.4
by MK 09 Jul '26

09 Jul '26

Hi everyone, I have a two-server setup where all user data from the actively used server is periodically transferred to the second server using "doveadm backup". For this, I currently use a script that caches a list of all users (containing only the usernames) via "doveadm user '*' " and then executes the command "doveadm backup -u [username] tcp:1.2.3.4" (target host) for each user. I use a similarly structured script for a daily "doveadm purge", where a purge is performed per user instead of a backup. Under version 2.3, I always ran both commands using the "-A" flag (doveadm purge -A and doveadm backup -A tcp:1.2.3.4). Since migrating from Dovecot 2.3 to 2.4, this no longer works. When running the purge, the process always aborts after a certain number of users with the following error message: doveadm(john(a)doe.de): Error: auth-master: userdb list: User listing returned failure It's not the same User allways but after nearly the same time or amount of users the script has processed. Since I couldn't identify the exact cause of the error and suspect it might be related to changes in how the SQL iterate query is integrated in the 2.4 configuration (I use MySQL as the backend) I switched to the script described above. Then since is used the new script I have a non-reproducible issue. After the initial data transfer (when the target is still empty) the amount of data is equal to the source. Then after one of the next transfers the data is twice as high. It is random as to which subsequent transfer triggers this. When comparing the quotas on the source and target server, the output is identical on both. Even running `quota recalc` makes no difference. If I check the user directories, I can see that the `storage` folder contains nearly double the number of files and used disk space per user. My second problem is that when I run the purge script on the second server (target), it sometimes deletes all emails for all users, also non-reproducible. Afterwards, all files under "storage" are gone, and the quota shows 0 emails. I did not have this issue with the exactly same purge script on the first server which is the source for the backup. The version change was during the update from Debian 12 to 13, involving an upgrade of Dovecot from version 2.3.19 to 2.4.1. (both packages from debian repo) We use MySQL as the backend and mdbox as the storage format. I hope some can help me to solve this issue. Greetings, Oliver

2 1