September 2007 - dovecot

[Dovecot] Strange error message
by Rich Winkel 22 Sep '07

22 Sep '07

I apologise if this is a faq but I couldn't find it in the archives. FreeBSD math 4.11-RELEASE-p26 FreeBSD 4.11-RELEASE-p26 dovecot version 1.0.3 x86 cpu local disk (ufs) Trying to run "deliver" from user's .forward file. sendmail configured with smrsh, forward file says: | "deliver" Imap seems to work fine, but deliver says: deliver(rw): mbox read/write lock list settings are invalid. Lock ordering must be the same with both, and write locks must contain all read locks (and possibly more) #dovecot -n # 1.0.3: /usr/local/etc/dovecot.conf base_dir: /var/run/dovecot/ listen: localhost:996 ssl_disable: yes login_dir: /var/run/dovecot/login login_executable: /usr/local/libexec/dovecot/imap-login login_greeting_capability: yes first_valid_uid: 100 mail_extra_groups: mail mail_location: mbox:~/mail:INBOX=/var/mail/%u:INDEX=/var/spool/dovecot_indexes/%u lock_method: flock mbox_write_locks: flock auth default: passdb: driver: pam userdb: driver: passwd Any help would be much appreciated!! Rich

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[Dovecot] Binary packagers: BSD license issues
by Timo Sirainen 22 Sep '07

22 Sep '07

Adding this SHA256 code made me read the BSD license once again. It says: * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. Then there are a few files from Cyrus as well which contain: * 4. Redistributions of any form whatsoever must retain the following * acknowledgment: * "This product includes software developed by Computing Services * at Carnegie Mellon University (http://www.cmu.edu/computing/)" And something similar in utc-mktime.c for Berkeley university as well. I think I'd really like to get rid of those base64.c and utc-mktime.c exceptions.. There's probably also an easier/faster way to implement utc_mktime(). Anyway.. Currently these copyrights or acknowledgments aren't listed anywhere else than in the source files. I don't know if binary packagers have added those, but somehow I doubt it. So I think I should add these to COPYING file somehow. Any suggestions? Perhaps appending something like this: src/lib/sha1.c, sha2.c : BSD license * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. * All rights reserved. * Copyright (C) 2005, 2007 Olivier Gay <olivier.gay(a)a3.epfl.ch> * All rights reserved. * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the project nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. src/lib/base64.c, utc-mktime.c : * Copyright (c) 2000 Carnegie Mellon University. All rights reserved. * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. The name "Carnegie Mellon University" must not be used to * endorse or promote products derived from this software without * prior written permission. For permission or any other legal * details, please contact * Office of Technology Transfer * Carnegie Mellon University * 5000 Forbes Avenue * Pittsburgh, PA 15213-3890 * (412) 268-4387, fax: (412) 268-7395 * tech-transfer(a)andrew.cmu.edu * * 4. Redistributions of any form whatsoever must retain the following * acknowledgment: * "This product includes software developed by Computing Services * at Carnegie Mellon University (http://www.cmu.edu/computing/)" * * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. * Copyright (c) 1987, 1989, 1993 * The Regents of the University of California. All rights reserved. * This code is derived from software contributed to Berkeley by * Arthur David Olson of the National Cancer Institute. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE.

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[Dovecot] IDLE with inotify problem
by Michael Guntsche 22 Sep '07

22 Sep '07

Hi, I recently switched from courier imap to dovecot. With courier I had a working IDLE setup that informed me immediately when new mail arrived. With Dovecot it is different, sometimes i get an immediate result but most of the time it takes a rather long time for the notification to return to the client. For testing purposes I set mailbox_idle_check_interval = 1 and i now get the same behaviour as with couier (a new mail immediately causes a notification) but i am not sure that this is the right solution. Reading the comments in the config files I was under the impression that this is not needed if dovecot uses inotify. Setup: Kernel 2.6.22.1 with inotify dovecot 1.0.3 from debian unstable Build options: ioloop=epoll notify=inotify ipv6 openssl So my question is can I check that dovecot is actually using inotify? Kind regards, Michael

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[Dovecot] Problems with quota dict in 1.1.alpha4
by arvids 22 Sep '07

22 Sep '07

Hello, there are problems with quota dict when multiple dovecot deliver processes are launched in parallel. It can be reproduced by sending a mail with multiple different recipients - the mail is delivered OK to all recipients, but the quota are not updated correctly in sql. I looked at the code and it seems that the problem is somewhere in dict cache. If I configure in Postfix max number of deliver processes to 1, dict quota is updated correctly. postconf -n output: # 1.1.alpha4: /usr/local/dovecot/etc/dovecot.conf base_dir: /var/run/dovecot/ syslog_facility: local0 protocols: pop3 ssl_disable: yes disable_plaintext_auth: no login_dir: /var/run/dovecot/login login_executable: /usr/local/dovecot/libexec/dovecot/pop3-login login_greeting: Server. login_process_per_connection: no login_process_size: 64 verbose_proctitle: yes first_valid_uid: 95 first_valid_gid: 95 mail_uid: 95 mail_gid: 95 mail_location: maildir:~/Maildir mail_debug: yes fsync_disable: yes mail_executable: /usr/local/dovecot/libexec/dovecot/pop3 mail_plugins: quota mail_plugin_dir: /usr/local/dovecot/lib/dovecot/pop3 pop3_enable_last: yes pop3_client_workarounds: outlook-no-nuls oe-ns-eoh auth default: mechanisms: plain login digest-md5 cram-md5 apop cache_size: 2048 cache_ttl: 28800 cache_negative_ttl: 60 user: doveauth verbose: yes debug: yes debug_passwords: yes passdb: driver: sql args: /usr/local/dovecot/etc/dovecot-sql.conf userdb: driver: prefetch userdb: driver: sql args: /usr/local/dovecot/etc/dovecot-sql.conf socket: type: listen master: path: /var/run/dovecot/auth-master mode: 384 user: vmail group: vmail plugin: quota: dict:::proxy:/var/run/dovecot/dict-server:quotadict dict: quotadict: mysql:/usr/local/dovecot/etc/dovecot-sql-dict-quota.conf Regards, Arvids

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[Dovecot] Feature Request for Proxy
by Ed W 22 Sep '07

22 Sep '07

Hi, Quick feature request for the proxy function: I have a couple of machines which are all customer facing and customer mailbox lives on any one of them. Customer can login to any machine and the proxy feature then forwards them to the correct machine (often the machine they are already connected to). However, right now if the SQL query simply returns the IP of the correct machine, and this happens to be the same machine that the connection is already on, then we get the auth process stuck in an infinite loop (and generating a lot of log files...) The quick fix is to customise each installation and add some kind of WHERE clause to change the results IF result is already the same as the machine we are on. However, this is error prone when setting up new machines and it's easy to forget or make a typo adjusting the config files. In my case I am using vservers and it's quite neat to be able to simply copy the whole image and fire it up on a new IP to test an upgrade, etc, hence easy to mess up adjusting the conf files when creating a new image. Any suggestions on how this could be done more dynamically, or else could I raise a feature request that the auth process somehow realises when it's being forwarded to an IP address that it's actually listening on already already (ie it's a request which loops back to itself), thus simplifying the config files? I haven't cracked open the code, but it sounds somewhat possible to check the list of IP addresses we are currently listening on and check that the proxy dest isn't among them? Cheers Ed W

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[Dovecot] maildir rename_subfolders() and listescape interaction
by pod 22 Sep '07

22 Sep '07

I'd like to flag a problem we are observing that looks like it is caused by the listescape-plugin.c. I realize that this plugin is not part of the standard Dovecot 1.0 distribution but I would appreciate any insights or suggestions for fixes that anyone is kind enough to offer. The problem concerns subfolder renames when used in conjunction with Maildir folders (I've not tested this against any other folder type). Without listescape plugin: mail_location: maildir:%h/Maildir:INDEX=%h/index:CONTROL=%h/control mail_plugins(default): quota imap_quota mail_plugins(imap): quota imap_quota namespace: type: private separator: / inbox: yes 01 LIST "" * * LIST (\HasNoChildren) "/" "INBOX" 01 OK List completed. 02 CREATE a 02 OK Create completed. 03 CREATE a/b 03 OK Create completed. 04 LIST "" * * LIST (\HasChildren) "/" "a" * LIST (\HasNoChildren) "/" "INBOX" * LIST (\HasNoChildren) "/" "a/b" 04 OK List completed. 05 RENAME a c 05 OK Rename completed. 06 LIST "" * * LIST (\HasChildren) "/" "c" * LIST (\HasNoChildren) "/" "INBOX" * LIST (\HasNoChildren) "/" "c/b" 06 OK List completed. 07 LOGOUT * BYE Logging out 07 OK Logout completed. With listescape plugin: mail_location: maildir:%h/Maildir:INDEX=%h/index:CONTROL=%h/control mail_plugins(default): quota imap_quota listescape mail_plugins(imap): quota imap_quota listescape namespace: type: private separator: / inbox: yes 01 LIST "" * * LIST (\HasNoChildren) "/" "INBOX" 01 OK List completed. 02 CREATE a 02 OK Create completed. 03 CREATE a/b 03 OK Create completed. 04 LIST "" * * LIST (\HasChildren) "/" "a" * LIST (\HasNoChildren) "/" "INBOX" * LIST (\HasNoChildren) "/" "a/b" 04 OK List completed. 05 RENAME a c 05 NO Internal error occurred. Refer to server log for more information. [2007-08-30 19:33:41] 06 LIST "" * * LIST (\HasNoChildren) "/" "a/b" * LIST (\HasNoChildren) "/" "c" * LIST (\HasNoChildren) "/" "INBOX" 06 OK List completed. 07 LOGOUT * BYE Logging out 07 OK Logout completed. Seemingly the only relevant log entry is @4000000046d70d8f1f72b66c dovecot: Error: IMAP(pod): rename(/srv/mail/home/test0/pod/Maildir/.a/b, /srv/mail/home/test0/pod/Maildir/.c/b) failed: No such file or directory Note the response to tag 05 in each case. The 06 list response in the listescape case is not unexpected given the nature of the failure. My initial reading of rename_subfolders() from maildir-storage.c suggests that the calls through maildir_mailbox_list_init() and maildir_mailbox_list_next() are returning "external" style names (i.e. ones that present "/" as the hierarchy separator) to rename_subfolders(), which is an "internal" helper function. This is supported by the logged error message. I am afraid I am yet to get my head around the actual code path and the escaping and unescaping that is going on so am not able to suggest a fix as yet.

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[Dovecot] Dovecot as LDA issues - please help
by Placid Publishing, LLC 22 Sep '07

22 Sep '07

I'm trying to get dovecot to work as an LDA with dspam; so I can run the dspam dovecot plugin for drag and drop spam/ham learning. Here is my config info: Version 1.0.5 base_dir: /var/run/dovecot/ protocols: imap imaps pop3 pop3s ssl_cipher_list: ALL:!LOW login_dir: /var/run/dovecot/login login_executable(default): /usr/local/libexec/dovecot/imap-login login_executable(imap): /usr/local/libexec/dovecot/imap-login login_executable(pop3): /usr/local/libexec/dovecot/pop3-login login_greeting: Welcome Mail. login_processes_count: 1 login_max_processes_count: 10 max_mail_processes: 20 verbose_proctitle: yes first_valid_uid: 1000 first_valid_gid: 1000 mail_extra_groups: mail mail_location: maildir:/usr/local/virtual/%d/%n mail_debug: yes maildir_copy_with_hardlinks: yes mail_executable(default): /usr/local/libexec/dovecot/imap mail_executable(imap): /usr/local/libexec/dovecot/imap mail_executable(pop3): /usr/local/libexec/dovecot/pop3 mail_plugins(default): dspam mail_plugins(imap): dspam mail_plugins(pop3): mail_plugin_dir(default): /usr/local/lib/dovecot/imap mail_plugin_dir(imap): /usr/local/lib/dovecot/imap mail_plugin_dir(pop3): /usr/local/lib/dovecot/pop3 imap_client_workarounds(default): delay-newmail outlook-idle netscape-eoh tb-extra-mailbox-sep imap_client_workarounds(imap): delay-newmail outlook-idle netscape-eoh tb-extra-mailbox-sep imap_client_workarounds(pop3): outlook-idle pop3_no_flag_updates(default): no pop3_no_flag_updates(imap): no pop3_no_flag_updates(pop3): yes pop3_lock_session(default): no pop3_lock_session(imap): no pop3_lock_session(pop3): yes pop3_uidl_format(default): pop3_uidl_format(imap): pop3_uidl_format(pop3): %08Xu%08Xv pop3_client_workarounds(default): pop3_client_workarounds(imap): pop3_client_workarounds(pop3): outlook-no-nuls oe-ns-eoh auth default: mechanisms: plain login passdb: driver: sql args: /usr/local/etc/dovecot-sql.conf userdb: driver: prefetch userdb: driver: sql args: /usr/local/etc/dovecot-sql.conf socket: type: listen client: path: /var/spool/postfix/private/auth mode: 432 user: postfix group: postfix master: path: /var/run/dovecot/auth-master mode: 432 user: vmail dovecot-sql config: driver = mysql password_query = SELECT password, 1011 AS uid, 1011 AS gid FROM users WHERE userid = '%u' user_query = SELECT 1011 AS uid, 1011 AS gid FROM users WHERE userid = '%u' dspam.conf (for delivery): TrustedDeliveryAgent "/usr/local/libexec/dovecot/deliver -d %u" UntrustedDeliveryAgent "/usr/local/libexec/dovecot/deliver -d %u" QuarantineAgent "/usr/local/libexec/dovecot/deliver -d %u -m Junk The error I get when running /usr/local/libexec/dovecot/deliver -c dovecot.conf -d username Sep 19 22:55:57 pelorus dovecot: auth-worker(default): mysql: Connected to localhost (db) Sep 19 22:55:57 pelorus deliver(support): auth input: support Sep 19 22:55:57 pelorus deliver(support): auth input: uid=1011 Sep 19 22:55:57 pelorus deliver(support): auth input: gid=1011 Sep 19 22:55:57 pelorus deliver(support): chdir(/root) failed: Permission denied Sep 19 22:55:57 pelorus deliver(support): maildir: data=/usr/local/virtual//support Sep 19 22:55:57 pelorus deliver(support): maildir: root=/usr/local/virtual//support, index=/usr/local/virtual//support, control=, inbox= maillog output when trying to deliver mail: Sep 19 22:57:13 pelorus postfix/smtpd[38846]: connect from py-out-1112.google.com[64.233.166.179] Sep 19 22:57:14 pelorus postfix/smtpd[38846]: NOQUEUE: filter: RCPT from py-out-1112.google.com[64.233.166.179]: <user(a)domain.com>: Recipient address triggers FILTER dspam:unix:/var/run/dspam/dspam.sock; from=<user(a)gmail.com> to=<support(a)exotixboard.com> proto=ESMTP helo=<py-out-1112.google.com> Sep 19 22:57:14 pelorus postfix/smtpd[38846]: B868B6CF83: client=py-out-1112.google.com[64.233.166.179] Sep 19 22:57:14 pelorus postfix/cleanup[38853]: B868B6CF83: message-id=<436c6f2f0709192057w17904ae5m83655736dc01929a(a)mail.gmail.com> Sep 19 22:57:14 pelorus postfix/qmgr[33660]: B868B6CF83: from=<user(a)gmail.com>, size=2040, nrcpt=1 (queue active) *Sep 19 22:57:14 pelorus dspam[33675]: Delivery agent returned exit code 67: /usr/local/libexec/dovecot/deliver -d user(a)domain.com* Sep 19 22:57:14 pelorus postfix/lmtp[38854]: B868B6CF83: to=<user(a)domain.com>, relay=mail2.domain.com[/var/run/dspam/dspam.sock], delay=1, delays=1/0/0/0.02, dsn=4.3.0, status=deferred (host mail2.exotixboard.com[/var/run/dspam/dspam.sock] said: 421 4.3.0 <user(a)domain.com> Auto-Whitelisted (in reply to end of DATA command)) My virtual users directory (/usr/local/virtual) is chowned vmail:vmail is chmodded 0777 for testing purposes. My question is, how can I get this to work? What is the "Sep 19 22:55:57 pelorus deliver(support): chdir(/root) failed: Permission denied"error from? Why doesn't the deliver work? Any help, input, or suggestions would be greatly appreciated.

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[Dovecot] Multiple SSL certs
by Noah Kantrowitz 22 Sep '07

22 Sep '07

I am trying to find a way to have the SSL cert used by Dovecot be dependent on the local IP address. So far the only ways I have found is to either have two different instances running (annoying because I would need to argue with the init scripts a lot) or use the old, undocumented server{} sections. Is the latter an acceptable way to do this, or is there something better? --Noah Kantrowitz

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[Dovecot] deliver assertion failure
by Jasper Bryant-Greene 22 Sep '07

22 Sep '07

Deliver from latest 1.1 HG with sieve also from latest 1.1 HG is dying with an assertion failure when it delivers to my mailbox. Other mailboxes on the same system are unaffected, but I can read my mailbox fine through IMAP. Dovecot and sieve were compiled with -march=nocona -pipe -ggdb I've commented out my entire sieve script and the problem still occurs. file index-mail-headers.c: line 590 (index_mail_get_raw_headers): assertion failed: (ret != -1) - Last output repeated twice - Raw backtrace: /usr/libexec/dovecot/deliver(i_syslog_panic_handler+0x2b) [0x493125] -> /usr/libexec/dovecot/deliver(i_fatal+0) [0x492b17] -> /usr/libexec/dovecot/deliver [0x44f7cf] -> /usr/libexec/dovecot/deliver(index_mail_get_first_header+0x30) [0x44fb9b] -> /usr/libexec/dovecot/deliver(mail_get_first_header+0x3a) [0x47ca3d] -> /usr/libexec/dovecot/deliver(deliver_get_return_address+0x21) [0x41453b] -> /usr/lib/dovecot/lda/lib90_cmusieve_plugin.so(cmu_sieve_run+0x14b) [0x2b3687f194a1] -> /usr/lib/dovecot/lda/lib90_cmusieve_plugin.so [0x2b3687f169ba] -> /usr/libexec/dovecot/deliver(main+0x8dc) [0x415c4d] -> /lib/libc.so.6(__libc_start_main+0xe3) [0x2b3687cf6533] -> /usr/libexec/dovecot/deliver [0x4137a9] Jasper

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[Dovecot] v1.1.alpha4 released / about dbox
by Timo Sirainen 22 Sep '07

22 Sep '07

http://dovecot.org/releases/1.1/alpha/dovecot-1.1.alpha4.tar.gz http://dovecot.org/releases/1.1/alpha/dovecot-1.1.alpha4.tar.gz.sig Lots of fixes since alpha3. Also includes the dbox rewrite. Currently dbox works properly only in one-message-per-file mode. I'm not actually even sure how good idea it would be to use it with multiple-messages-per-file mode. But I guess it won't hurt to finish its implementation and see. :) As you can see I haven't been replying much to the mailing list lately. My school started again, which meant that I had to start sleeping again at night instead of at day :) Doing that always takes a few weeks of feeling too tired to get much of anything done. Hopefully that goes away soon. A bit more about dbox: Originally I had thought that it'd be good to have multiple messages per file. The bad thing about that is that it works badly without fcntl locks, which don't work all that great with NFS. So I changed my plans a bit so that dbox also supports one-message-per-file behavior where it doesn't need locking much. (Multiple-messages-per-file is still supported by the format, but currently the code is not fully working.) dbox files begin with a header, then they have the message data and at the end of file there's a metadata block. Metadata contains things like message flags, keywords, received date and so on. When a flag/keyword is updated, the change is normally done only to index files. This is why dovecot.index and dovecot.index.log files are important with dbox format, they contain flag changes that haven't been written anywhere else. But since there's still a chance that index files could break (although v1.1 tries harder than v1.0 to fix problems), it would be nice if the flags/keywords were written to metadata block once in a while. So if the index files are lost, flag changes wouldn't be completely lost. Metadata updates of course use disk I/O so they shouldn't be done too often. I was thinking that the metadata could be updated: - if IMAP connection has been idling for 4 hours (not changing flags) - when closing mailbox and there are changes older than 4h - immediately if there are changes older than 24h (whenever mailbox is being synced, e.g. SELECT/NOOP/STATUS) Or something like that. Those rules can of course be changed, but I'm not sure if I should bother making them configurable from dovecot.conf. There are already too many settings.

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