- dovecot - dovecot.org

questions about maildir to mdbox migration
by Dave McGuire 28 Sep '17

28 Sep '17

Hi folks! I converted some of the spools on my mail server from maildir to mdbox. It went smoothly and the performance has been great. However, I have two questions regarding the process. First, I failed to notice the fairly low default mdbox_rotate_size, and I changed it in dovecot.conf after the migration. Is it possible to somehow make that change retroactive, to coalesce the couple thousand "storage/m.*" files that are anywhere from a few hundred bytes up to a few megabytes, into a smaller number of larger files, without re-doing the migration? Second, I'd like to delete the old maildir files and directories to reclaim the space in the filesystem, but it's not clear to me which ones I can safely delete, i.e. ones upon which my new mdbox-based spools no longer depend. I know maildir uses new, tmp, and cur directories, but in the spool directory there are also files like dovecot-uidlist, dovecot-uidvalidity, dovecot.index.cache, dovecot.index.log, dovecot.mailbox.log, as well as separate directories for each of my mail folders containing their own new, tmp, and cur directories and their own dovecot* files. Can someone offer some guidance regarding which ones I can safely remove? Thanks, -Dave -- Dave McGuire, AK4HZ New Kensington, PA

2 2

Panic
by Matthijs Kooijman 28 Sep '17

28 Sep '17

(I'm not subscribed, please keep me CC'd) Hi, since a few months I'm experiencing repeated dovecot crashes. I mostly see them in the logs, I haven't had any users complain, so I haven't looked closely until now. I was originally using an older version fro mDebian and hoped that a newer future version would already fix this, but I just upgraded to version 1:2.2.32-2 from Debian testing, and the problem persists. This crash sometimes happens occasionally, but often happens repeatedly for some time (presumably a client keeps retrying) but can also be gone for hours or days (presumably the client no longer connects). I haven't been able to definitively figure out what client causes this, but based on the user ID I suspect it is Mail.app on OSX. I managed to get a core dump, which gave me the stacktrace below. I've also attached my config file. If any other details are relevant, just ask and I can squeeze them out of the core dump (but I'd rather not publicly share the file). I can probably set up rawlog to capture the actual IMAP session if needed, though I have no time for that right now. Gr. Matthijs 51 ../sysdeps/unix/sysv/linux/raise.c: No such file or directory. (gdb) bt #0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:51 #1 0x00007fc5eed9c3fa in __GI_abort () at abort.c:89 #2 0x00007fc5ef1a609a in default_fatal_finish (type=LOG_TYPE_PANIC, status=status@entry=0) at failures.c:201 #3 0x00007fc5ef1a619a in i_internal_fatal_handler (ctx=0x7ffc553b38d0, format=<optimized out>, args=<optimized out>) at failures.c:670 #4 0x00007fc5ef136cf8 in i_panic (format=format@entry=0x7fc5ef52e880 "file %s: line %d (%s): assertion failed: (%s)") at failures.c:275 #5 0x00007fc5ef47f998 in mailbox_copy_int (_ctx=_ctx@entry=0x7ffc553b3ab0, mail=<optimized out>) at mail-storage.c:2473 #6 0x00007fc5ef47f9ff in mailbox_copy (_ctx=_ctx@entry=0x7ffc553b3ab0, mail=<optimized out>) at mail-storage.c:2489 #7 0x000055bae72a2f5f in fetch_and_copy (copy_count_r=<synthetic pointer>, src_uidset_r=<synthetic pointer>, search_args=<optimized out>, src_trans_r=0x7ffc553b3a88, t=<optimized out>, move=<optimized out>, cmd=0x55bae816d5e8) at cmd-copy.c:72 #8 cmd_copy_full (cmd=0x55bae816d5e8, move=false) at cmd-copy.c:139 #9 0x000055bae72afd9c in command_exec (cmd=cmd@entry=0x55bae816d5e8) at imap-commands.c:200 #10 0x000055bae72ae322 in client_command_input (cmd=<optimized out>, cmd@entry=0x55bae816d5e8) at imap-client.c:1088 #11 0x000055bae72ae3bc in client_command_input (cmd=<optimized out>) at imap-client.c:1148 #12 0x000055bae72ae77d in client_handle_next_command (remove_io_r=<synthetic pointer>, client=0x55bae816bcf8) at imap-client.c:1190 #13 client_handle_input (client=0x55bae816bcf8) at imap-client.c:1202 #14 0x000055bae72aeccc in client_input (client=0x55bae816bcf8) at imap-client.c:1249 #15 0x00007fc5ef1bb742 in io_loop_call_io (io=0x55bae816d4e0) at ioloop.c:599 #16 0x00007fc5ef1bcd8e in io_loop_handler_run_internal (ioloop=ioloop@entry=0x55bae8153990) at ioloop-epoll.c:223 #17 0x00007fc5ef1bb7d6 in io_loop_handler_run (ioloop=ioloop@entry=0x55bae8153990) at ioloop.c:648 #18 0x00007fc5ef1bb988 in io_loop_run (ioloop=0x55bae8153990) at ioloop.c:623 #19 0x00007fc5ef141353 in master_service_run (service=0x55bae8153830, callback=<optimized out>) at master-service.c:666 #20 0x000055bae72a1139 in main (argc=<optimized out>, argv=<optimized out>) at main.c:491 (gdb) up 9 #9 0x000055bae72afd9c in command_exec (cmd=cmd@entry=0x55bae816d5e8) at imap-commands.c:200 200 finished = cmd->func(cmd); (gdb) p *cmd $14 = {prev = 0x0, next = 0x0, client = 0x55bae816bcf8, pool = 0x55bae816d5c0, tag = 0x55bae816d750 "7.119309", name = 0x55bae816d760 "UID COPY", args = 0x55bae816d770 "20004 INBOX", human_args = 0x55bae816d780 "20004 INBOX", cmd_flags = COMMAND_FLAG_BREAKS_SEQS, tagline_reply = 0x0, func = 0x55bae72a33e0 <cmd_copy>, context = 0x0, module_contexts = {arr = {buffer = 0x55bae816d6e8, element_size = 8}, v = 0x55bae816d6e8, v_modifiable = 0x55bae816d6e8}, parser = 0x55bae8157aa0, state = CLIENT_COMMAND_STATE_WAIT_INPUT, stats = {start_time = {tv_sec = 1506507612, tv_usec = 777163}, last_run_timeval = {tv_sec = 1506507612, tv_usec = 777163}, start_ioloop_wait_usecs = 46340, running_usecs = 0, lock_wait_usecs = 0, bytes_in = 0, bytes_out = 0}, stats_start = {timeval = { tv_sec = 1506507612, tv_usec = 777241}, lock_wait_usecs = 0, bytes_in = 91, bytes_out = 852}, sync = 0x0, uid = 1, cancel = 0, param_error = 0, search_save_result = 0, search_save_result_used = 0, temp_executed = 0, tagline_sent = 0, executing = 1} (gdb) down #8 cmd_copy_full (cmd=0x55bae816d5e8, move=false) at cmd-copy.c:139 139 ret = fetch_and_copy(cmd, move, t, &src_trans, search_args, (gdb) #7 0x000055bae72a2f5f in fetch_and_copy (copy_count_r=<synthetic pointer>, src_uidset_r=<synthetic pointer>, search_args=<optimized out>, src_trans_r=0x7ffc553b3a88, t=<optimized out>, move=<optimized out>, cmd=0x55bae816d5e8) at cmd-copy.c:72 72 if (mailbox_copy(&save_ctx, mail) < 0) (gdb) #6 0x00007fc5ef47f9ff in mailbox_copy (_ctx=_ctx@entry=0x7ffc553b3ab0, mail=<optimized out>) at mail-storage.c:2489 2489 return mailbox_copy_int(_ctx, mail); (gdb) #5 0x00007fc5ef47f998 in mailbox_copy_int (_ctx=_ctx@entry=0x7ffc553b3ab0, mail=<optimized out>) at mail-storage.c:2473 2473 i_assert(!ctx->unfinished); (gdb) #4 0x00007fc5ef136cf8 in i_panic (format=format@entry=0x7fc5ef52e880 "file %s: line %d (%s): assertion failed: (%s)") at failures.c:275 275 fatal_handler(&ctx, format, args);

3 7

Dovecot and Self-signed issue
by Michael A. Peters 28 Sep '17

28 Sep '17

I use dovecot on several servers. One of them uses a self-signed cert, it's just me. It worked fine until yesterday when I upgraded my desktop (NOT the server) to CentOS 7.4 Now thunderbird complains when it starts up, and won't let me confirm the security exception. On the server the following error occurs in the log: Sep 25 20:17:49 librelamp dovecot: imap-login: Disconnected (no auth attempts in 1 secs): user=<>, rip=2600:1010:b064:f260:e83e:562d:2316:18df, lip=2600:3c01::f03c:91ff:fee4:310c, TLS handshaking: SSL_accept() failed: error:14094418:SSL routines:SSL3_READ_BYTES:tlsv1 alert unknown ca: SSL alert number 48, session=<u7agQAlasK8mABAQsGTyYOg+Vi0jFhjf> I believe this is a client issue, as it worked just fine in CentOS 7.3 client, but I am hoping this has been seen and fixed before.

3 6

dsync: assert panic on mbox // no INBOX sync on hybrid mbox/maildir
by David Gardner 27 Sep '17

27 Sep '17

Hi, This (hopefully!) might be a case of user error, as I'm new to dovecot... Alternatively it might be some confusion in an index, since I've been mucking about trying different things in my configuration files and had frequent crashes. I'm trying to sync 2 (LAN) hosts, ideally to have full automatic replication happening. They both have hybrid mbox INBOX and maildir++ folders, using namespaces, as suggested in the wiki. I might have deviated the config from the wiki version, in trying to get things working. Both hosts communicate perfectly with an external IMAP client (thunderbird). Replication is working, but only partially - it is syncing the folders but not INBOX. I've thus been trying various things to try to get the INBOX to sync. The crash is only happening one of the 2 hosts which I've named crashhost for this report. The process crashes no matter which host starts the sync. With a second user, the crash happens on the other host crashhost: Ubuntu 16.04, x86_64, laptop, Dovecot 2.2.22, and Dovecot 2.2.32 (from debian sid package, locally compiled) otherhost: Ubuntu 16.04, x86_64, desktop, Dovecot 2.2.22, and Dovecot 2.2.32 (from debian sid package, locally compiled) RESULTS: 1) doveadm sync -f -u david tcp:otherhost synchronises the folders, but does not touch INBOXes. 2) doveadm sync -f -m INBOX -u david tcp:otherhost Does not touch INBOXes 3) doveadm sync -n '#mbox/' -f -u david tcp:otherhost dsync-local(david): Panic: file mbox-lock.c: line 800 (mbox_lock): assertion failed: (lock_type == F_RDLCK || mbox->mbox_lock_type != F_RDLCK) I added some debug code, the assertion failure is being triggered by a call to mbox-lock() with: locktype=F_WRCLK mbox->mbox_lock_type=F_RDLCK, mbox->external_transactions=1 The config files on the 2 hosts only differ by the hostnames they're supposed to be syncing to. $ dovecot -n # 2.2.32 (dfbe293d4): /etc/dovecot/dovecot.conf # Pigeonhole version 0.4.20 (7cd71ba) # OS: Linux 4.10.0-35-generic x86_64 Ubuntu 16.04.3 LTS doveadm_password = # hidden, use -P to show it doveadm_port = 12346 imapc_host = crashhost imapc_password = # hidden, use -P to show it imapc_port = 993 imapc_ssl = imaps imapc_ssl_verify = no imapc_user = %u mail_location = maildir:~/mail mail_plugins = " notify replication" mail_privileged_group = mail namespace { inbox = no list = yes location = prefix = separator = / subscriptions = yes } namespace inbox { hidden = yes inbox = yes list = no location = mbox:~/nomail:INBOX=/var/mail/%u:INDEX=/var/spool/mailindex/%u mailbox Drafts { special_use = \Drafts } mailbox Junk { special_use = \Junk } mailbox Sent { special_use = \Sent } mailbox "Sent Messages" { special_use = \Sent } mailbox Trash { special_use = \Trash } prefix = "#mbox/" separator = / type = private } passdb { args = scheme=CRYPT username_format=%u /etc/dovecot/users driver = passwd-file } plugin { mail_replica = tcp:otherhost:12346 } protocols = " imap" service aggregator { fifo_listener replication-notify-fifo { mode = 0666 user = vmail } unix_listener replication-notify { mode = 0666 user = vmail } } service config { unix_listener config { user = vmail } } service doveadm { inet_listener { port = 12346 } user = root } service replicator { process_min_avail = 1 unix_listener replicator-doveadm { mode = 0666 } } ssl = required ssl_cert = </etc/dovecot/dovecot.pem ssl_client_ca_dir = /etc/ssl ssl_key = # hidden, use -P to show it userdb { args = username_format=%u /etc/dovecot/users driver = passwd-file } gdb) bt #0 0x00007f37f426e428 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:54 #1 0x00007f37f427002a in __GI_abort () at abort.c:89 #2 0x00007f37f469f7aa in ?? () from /usr/lib/dovecot/libdovecot.so.0 #3 0x00007f37f469f829 in default_fatal_handler () from /usr/lib/dovecot/libdovecot.so.0 #4 0x00007f37f46302a1 in i_panic () from /usr/lib/dovecot/libdovecot.so.0 #5 0x00007f37f49ac235 in mbox_lock () from /usr/lib/dovecot/libdovecot-storage.so.0 #6 0x00007f37f49adb11 in mbox_save_begin () from /usr/lib/dovecot/libdovecot-storage.so.0 #7 0x00007f37f49769a1 in mailbox_save_begin () from /usr/lib/dovecot/libdovecot-storage.so.0 #8 0x00007f37f496a2e8 in mail_storage_copy () from /usr/lib/dovecot/libdovecot-storage.so.0 #9 0x00007f37f3e332a5 in ?? () from /usr/lib/dovecot/modules/lib15_notify_plugin.so #10 0x00007f37f4976b73 in ?? () from /usr/lib/dovecot/libdovecot-storage.so.0 #11 0x00007f37f4976d89 in mailbox_move () from /usr/lib/dovecot/libdovecot-storage.so.0 #12 0x000055b45f0da448 in ?? () #13 0x000055b45f0db35a in ?? () #14 0x000055b45f0ddbc0 in dsync_mailbox_import_changes_finish () #15 0x000055b45f0d8645 in dsync_brain_sync_mails () #16 0x000055b45f0d3df8 in dsync_brain_run () #17 0x000055b45f0d4140 in ?? () #18 0x000055b45f0ea3ff in ?? () #19 0x00007f37f46b4c82 in io_loop_call_io () from /usr/lib/dovecot/libdovecot.so.0 #20 0x00007f37f46b6309 in io_loop_handler_run_internal () from /usr/lib/dovecot/libdovecot.so.0 #21 0x00007f37f46b4d1c in io_loop_handler_run () from /usr/lib/dovecot/libdovecot.so.0 #22 0x00007f37f46b4ec8 in io_loop_run () from /usr/lib/dovecot/libdovecot.so.0 #23 0x000055b45f0bb4c2 in ?? () #24 0x000055b45f0bd91c in ?? () #25 0x000055b45f0be5aa in ?? () #26 0x000055b45f0beeda in doveadm_mail_try_run () #27 0x000055b45f0ae47c in main ()

3 3

Quota-status service on Director
by Michael Kliewe 27 Sep '17

27 Sep '17

Hello, I'm trying to configure the quota-status service, but it seems I'm not successful with my director setup (2.2.9). I activate the quota-status service like this on my director server: $ cat 91-quota-status.conf ## ## Quota-Status configuration. ## # Load Module quota-status and listen on TCP/IP Port for connections. service quota-status { executable = quota-status -p postfix inet_listener { address = 10.0.1.44 port = 12340 } client_limit = 1 } # Plugin configuration. # Return messages for requests by quota status: success, nouser and overquota. plugin { quota_status_success = DUNNO quota_status_nouser = DUNNO quota_status_overquota = "552 5.2.2 Mailbox is over quota" } After restarting the director service I try to query the quota status service: printf "recipient=user(a)domain.de\nsize=100000\n\n" | nc 10.0.1.44 12340 The output is: action=DEFER_IF_PERMIT Invalid user settings. Refer to server log for more information. In the debug log of the director I see this: Feb 23 03:03:09 director01 dovecot: auth: Debug: userdb out: USER 1 user(a)domain.de mail=mdbox:/mnt/data01/domain.de/user/maildir home=/mnt/data01/domain.de/user proxy=Y master=<hidden> pass=<hidden> uid=5000 gid=1 quota_rule=*:storage=60593 quota_rule2=*:messages=100000 Feb 23 03:03:09 director01 dovecot: quota-status(user(a)domain.de): Error: user user(a)domain.de: Initialization failed: Namespace '': mkdir(/mnt/data01/domain.de/user/maildir/mailboxes) failed: Permission denied (euid=5000(vmail) egid=1(daemon) missing +w perm: /mnt, dir owned by 0:0 mode=0755) So the quota status service tries to access the mailbox of the user ON THE DIRECTOR. But the director has not mounted the mailboxes of the users, that's what the backend dovecots are for (proxy=Y). So the quota-status query is not proxied to the dovecot backend server I would assume. Does that mean I have to start the quota-status service on the dovecot backend servers and access it from the Postfix server directly? Currently the Postfixes can only reach the directors, not the backend servers. Is it possible to use the quota-status service on the director? Thanks for any hints and help Michael

3 4

librmb: Mail storage on RADOS with Dovecot
by mj 25 Sep '17

25 Sep '17

Hi ceph-ers, The email below was posted on the ceph mailinglist yesterday by Wido den Hollander. I guess this could be interesting for user here as well. MJ -------- Forwarded Message -------- Subject: [ceph-users] librmb: Mail storage on RADOS with Dovecot Date: Thu, 21 Sep 2017 10:40:03 +0200 (CEST) From: Wido den Hollander <wido(a)42on.com> To: ceph-users(a)ceph.com Hi, A tracker issue has been out there for a while: http://tracker.ceph.com/issues/12430 Storing e-mail in RADOS with Dovecot, the IMAP/POP3/LDA server with a huge marketshare. It took a while, but last year Deutsche Telekom took on the heavy work and started a project to develop librmb: LibRadosMailBox Together with Deutsche Telekom and Tallence GmbH (DE) this project came to life. First, the Github link: https://github.com/ceph-dovecot/dovecot-ceph-plugin I am not going to repeat everything which is on Github, put a short summary: - CephFS is used for storing Mailbox Indexes - E-Mails are stored directly as RADOS objects - It's a Dovecot plugin We would like everybody to test librmb and report back issues on Github so that further development can be done. It's not finalized yet, but all the help is welcome to make librmb the best solution for storing your e-mails on Ceph with Dovecot. Danny Al-Gaaf has written a small blogpost about it and a presentation: - https://dalgaaf.github.io/CephMeetUpBerlin20170918-librmb/ - http://blog.bisect.de/2017/09/ceph-meetup-berlin-followup-librmb.html To get a idea of the scale: 4,7PB of RAW storage over 1.200 OSDs is the final goal (last slide in presentation). That will provide roughly 1,2PB of usable storage capacity for storing e-mail, a lot of e-mail. To see this project finally go into the Open Source world excites me a lot :-) A very, very big thanks to Deutsche Telekom for funding this awesome project! A big thanks as well to Tallence as they did an awesome job in developing librmb in such a short time. Wido

4 3

Different users having same home/mail_location?
by Tapio Sokura 24 Sep '17

24 Sep '17

Hello, Will I be breaking something if I have two users share the same home and/or mail_location (maildir format) in dovecot? Mail will only be delivered to the primary user, the other would be used every now and then to login via imap (webmail). This would be on a CentOS 7 box running dovecot from the packaging system, i.e. dovecot-2.2.10-8.el7 currently. The reason I'd like to do this is to have two ways to login to the same mailbox, one using username + password and the other otherusername + otherpassword + otp-token. Basically this "otherusername" would be for cases where I don't trust the client computer to not have a keylogger etc badness in it, but still need to see my mail. I have this kind of a dual-login setup via PAM for regular system user authentication and it's working ok. I'm just wondering about the dovecot part, whether dovecot will do Unexpected Things if more than one user have the same home and mail_location? If it makes any difference, the users can have separate homes, but the mailbox should be the same for usability. Tapio

4 6

Sieve vacation and srs
by azurit＠pobox.sk 23 Sep '17

23 Sep '17

Hi, is this already fixed? https://www.dovecot.org/pipermail/dovecot/2017-July/108688.html If so, which version of Dovecot includes fix for this? Thanks for info. azur

2 1

Panic: file dict-fs.c:
by Computerisms Corporation 22 Sep '17

22 Sep '17

Hi, Am I doing something wrong here, or is this an actual problem? I am trying to get the top level of a public Mailbox to be an actual mailbox, instead of just storing subfolders. I get what looks to be an identical error when running doveadm acl recalc as well doveadm acl debug Departments2/IT doveadm(root): Info: Mailbox 'IT' is in namespace 'Departments2/' doveadm(root): Info: Mailbox path: /mail/Departments2/.IT doveadm(root): Info: Per-user private flags in mailbox: \Seen doveadm(root): Info: User root has rights: lookup read write write-seen write-deleted insert post expunge doveadm(root): Info: Mailbox found from dovecot-acl-list doveadm(root): Info: Mailbox is in public namespace doveadm(root): Info: Mailbox Departments2/IT is visible in LIST doveadm acl debug Departments2 doveadm(root): Info: Mailbox '' is in namespace 'Departments2/' doveadm(root): Info: Mailbox path: /mail/Departments2 doveadm(root): Info: Per-user private flags in mailbox: \Seen doveadm(root): Info: User root has rights: lookup read write write-seen write-deleted insert post expunge doveadm(root): Error: Mailbox not found from dovecot-acl-list, rebuilding doveadm(root): Panic: file dict-fs.c: line 127 (fs_dict_iterate_init): assertion failed: ((flags & DICT_ITERATE_FLAG_RECURSE) == 0) doveadm(root): Error: Raw backtrace: /usr/local/lib/dovecot/libdovecot.so.0(+0x9a954) [0x7f36a1627954] -> /usr/local/lib/dovecot/libdovecot.so.0(+0x9a9d9) [0x7f36a16279d9] -> /usr/local/lib/dovecot/libdovecot.so.0(i_fatal+0) [0x7f36a15bc9a0] -> /usr/local/lib/dovecot/libdovecot.so.0(+0x30438) [0x7f36a15bd438] -> /usr/local/lib/dovecot/libdovecot.so.0(dict_iterate_init_multiple+0x74) [0x7f36a15f3bf4] -> /usr/local/lib/dovecot/libdovecot.so.0(dict_iterate_init+0x19) [0x7f36a15f3c69] -> /usr/local/lib/dovecot/lib01_acl_plugin.so(acl_lookup_dict_rebuild+0x392) [0x7f36a0de1ab2] -> /usr/local/lib/dovecot/lib01_acl_plugin.so(+0xa695) [0x7f36a0ddf695] -> /usr/local/lib/dovecot/lib01_acl_plugin.so(acl_backend_vfile_acllist_rebuild+0xd) [0x7f36a0ddf7cd] -> /usr/local/lib/dovecot/doveadm/lib10_doveadm_acl_plugin.so(+0x2552) [0x7f36a07b4552] -> /usr/local/lib/dovecot/doveadm/lib10_doveadm_acl_plugin.so(+0x27ff) [0x7f36a07b47ff] -> doveadm(+0x2a14d) [0x5624042e714d] -> doveadm(+0x2ac20) [0x5624042e7c20] -> doveadm(doveadm_cmd_ver2_to_mail_cmd_wrapper+0x22a) [0x5624042e89ea] -> doveadm(doveadm_cmd_run_ver2+0x515) [0x5624042f7125] -> doveadm(doveadm_cmd_try_run_ver2+0x37) [0x5624042f7177] -> doveadm(main+0x1ca) [0x5624042d85ba] -> /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf1) [0x7f36a120e2b1] -> doveadm(_start+0x2a) [0x5624042d897a] Aborted -- Bob Miller Cell: 867-334-7117 Office: 867-633-3760 www.computerisms.ca

1 0

Very high load
by absolutely_free＠libero.it 22 Sep '17

22 Sep '17

Hi, I am using dovecot 2.0.9 (official CentOS rpm), I am experiencing very high load issue. I think it is something related to my storage (/var/spool is about 3 TB and it is almost full). I noticed those kind of messages in /var/log/maillog: Warning: Maildir: Scanning /var/spool/pop/domains/domain.it/username/Maildir/cur took 100 seconds (14281 readdir()s, 0 rename()s to cur/) Warning: Maildir /var/spool/pop/domains/domain.it/username/Maildir: Synchronization took 103 seconds (0 new msgs, 0 flag change attempts, 0 expunge attempts) I wondering if there is something to try, at configuration level, to "mitigate" this.. I use Maildir format, MTA is postfix, I have many users (> 10000) with pop3/imap/webmail access. Physical server with 8 GB RAM and two CPU (Intel(R) Pentium(R) D CPU 3.00GHz) This is my dovecot's conf: auth_anonymous_username = anonymous auth_cache_negative_ttl = 1 hours auth_cache_size = 0 auth_cache_ttl = 1 hours auth_debug = no auth_debug_passwords = no auth_default_realm = auth_failure_delay = 2 secs auth_first_valid_uid = 500 auth_gssapi_hostname = auth_krb5_keytab = auth_last_valid_uid = 0 auth_master_user_separator = auth_mechanisms = plain login digest-md5 cram-md5 auth_realms = auth_socket_path = auth-userdb auth_ssl_require_client_cert = no auth_ssl_username_from_cert = no auth_use_winbind = no auth_username_chars = abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@ auth_username_format = auth_username_translation = auth_verbose = no auth_verbose_passwords = no auth_winbind_helper_path = /usr/bin/ntlm_auth auth_worker_max_count = 30 base_dir = /var/run/dovecot config_cache_size = 1 M debug_log_path = /var/log/dovecot.log default_client_limit = 1000 default_idle_kill = 60 default_internal_user = dovecot default_login_user = dovenull default_process_limit = 100 default_vsz_limit = 256 M deliver_log_format = msgid=%m: %$ dict_db_config = director_doveadm_port = 0 director_mail_servers = director_servers = director_user_expire = 15 mins disable_plaintext_auth = no dotlock_use_excl = no doveadm_socket_path = doveadm-server doveadm_worker_count = 0 first_valid_gid = 89 first_valid_uid = 89 hostname = imap_capability = imap_client_workarounds = imap_id_log = imap_id_send = imap_idle_notify_interval = 2 mins imap_logout_format = bytes=%i/%o imap_max_line_length = 64 k info_log_path = last_valid_gid = 0 last_valid_uid = 0 lda_mailbox_autocreate = no lda_mailbox_autosubscribe = no lda_original_recipient_header = libexec_dir = /usr/libexec/dovecot listen = *, :: lmtp_proxy = no lmtp_save_to_detail_mailbox = no lock_method = fcntl log_path = syslog log_timestamp = "%b %d %H:%M:%S " login_access_sockets = login_greeting = Dovecot ready. login_log_format = %$: %s login_log_format_elements = user=<%u> method=%m rip=%r lip=%l mpid=%e %c login_trusted_networks = mail_access_groups = mail_attachment_dir = mail_attachment_fs = sis posix mail_attachment_hash = %{sha1} mail_attachment_min_size = 128 k mail_cache_fields = flags mail_cache_min_mail_count = 0 mail_chroot = mail_debug = no mail_fsync = optimized mail_full_filesystem_access = no mail_gid = 89 mail_home = mail_location = maildir:/coraid-s2l2/domains mail_log_prefix = "%s(%u): " mail_max_keyword_length = 50 mail_max_lock_timeout = 0 mail_max_userip_connections = 10 mail_never_cache_fields = imap.envelope mail_nfs_index = no mail_nfs_storage = no mail_plugin_dir = /usr/lib64/dovecot mail_plugins = mail_privileged_group = mail_save_crlf = no mail_temp_dir = /tmp mail_uid = 89 mailbox_idle_check_interval = 30 secs mailbox_list_index_disable = no maildir_copy_with_hardlinks = yes maildir_stat_dirs = no maildir_very_dirty_syncs = no managesieve_client_workarounds = managesieve_implementation_string = Dovecot Pigeonhole managesieve_logout_format = bytes=%i/%o managesieve_max_compile_errors = 5 managesieve_max_line_length = 65536 managesieve_notify_capability = mailto managesieve_sieve_capability = fileinto reject envelope encoded-character vacation subaddress comparator-i;ascii-numeric relational regex imap4flags copy include variables body enotify environment mailbox date imapflags notify master_user_separator = mbox_dirty_syncs = yes mbox_dotlock_change_timeout = 2 mins mbox_lazy_writes = yes mbox_lock_timeout = 5 mins mbox_min_index_size = 0 mbox_read_locks = fcntl mbox_very_dirty_syncs = no mbox_write_locks = fcntl mdbox_preallocate_space = no mdbox_rotate_interval = 0 mdbox_rotate_size = 2 M mmap_disable = no namespace { hidden = no inbox = yes list = yes location = prefix = INBOX. separator = . subscriptions = yes type = private } passdb { args = /etc/dovecot/dovecot-sql.conf.ext deny = no driver = sql master = no pass = no } passdb { args = /etc/dovecot/dovecot-sql-crypt.conf.ext deny = no driver = sql master = no pass = no } plugin { sieve = ~/.dovecot.sieve sieve_dir = ~/sieve sieve_extensions = +notify +imapflags sieve_max_script_size = 1M } pop3_client_workarounds = pop3_enable_last = no pop3_fast_size_lookups = no pop3_lock_session = no pop3_logout_format = top=%t/%p, retr=%r/%b, del=%d/%m, size=%s pop3_no_flag_updates = no pop3_reuse_xuidl = no pop3_save_uidl = no pop3_uidl_format = %08Xu%08Xv postmaster_address = protocols = imap pop3 lmtp sieve quota_full_tempfail = no recipient_delimiter = + rejection_reason = Your message to <%t> was automatically rejected:%n%r rejection_subject = Rejected: %s sendmail_path = /usr/sbin/sendmail service anvil { chroot = empty client_limit = 0 drop_priv_before_exec = no executable = anvil extra_groups = group = idle_kill = 4294967295 secs privileged_group = process_limit = 1 process_min_avail = 1 protocol = service_count = 0 type = anvil unix_listener anvil-auth-penalty { group = mode = 0600 user = } unix_listener anvil { group = mode = 0600 user = } user = $default_internal_user vsz_limit = 18446744073709551615 B } service auth-worker { chroot = client_limit = 1 drop_priv_before_exec = no executable = auth -w extra_groups = group = idle_kill = 0 privileged_group = process_limit = 0 process_min_avail = 0 protocol = service_count = 1 type = unix_listener auth-worker { group = mode = 0600 user = $default_internal_user } user = vsz_limit = 18446744073709551615 B } service auth { chroot = client_limit = 4096 drop_priv_before_exec = no executable = auth extra_groups = group = idle_kill = 0 privileged_group = process_limit = 1 process_min_avail = 0 protocol = service_count = 0 type = unix_listener auth-client { group = mode = 0600 user = } unix_listener auth-login { group = mode = 0600 user = $default_internal_user } unix_listener auth-master { group = mode = 0600 user = } unix_listener auth-userdb { group = mode = 0600 user = } unix_listener login/login { group = mode = 0666 user = } user = $default_internal_user vsz_limit = 18446744073709551615 B } service config { chroot = client_limit = 0 drop_priv_before_exec = no executable = config extra_groups = group = idle_kill = 0 privileged_group = process_limit = 0 process_min_avail = 0 protocol = service_count = 0 type = config unix_listener config { group = mode = 0600 user = } user = vsz_limit = 18446744073709551615 B } service dict { chroot = client_limit = 1 drop_priv_before_exec = no executable = dict extra_groups = group = idle_kill = 0 privileged_group = process_limit = 0 process_min_avail = 0 protocol = service_count = 0 type = unix_listener dict { group = mode = 0600 user = } user = $default_internal_user vsz_limit = 18446744073709551615 B } service director { chroot = client_limit = 0 drop_priv_before_exec = no executable = director extra_groups = fifo_listener login/proxy-notify { group = mode = 00 user = } group = idle_kill = 4294967295 secs inet_listener { address = port = 0 ssl = no } privileged_group = process_limit = 1 process_min_avail = 0 protocol = service_count = 0 type = unix_listener director-admin { group = mode = 0600 user = } unix_listener director-userdb { group = mode = 0600 user = } unix_listener login/director { group = mode = 00 user = } user = $default_internal_user vsz_limit = 18446744073709551615 B } service dns_client { chroot = client_limit = 1 drop_priv_before_exec = no executable = dns-client extra_groups = group = idle_kill = 0 privileged_group = process_limit = 0 process_min_avail = 0 protocol = service_count = 0 type = unix_listener dns-client { group = mode = 0666 user = } unix_listener login/dns-client { group = mode = 0666 user = } user = $default_internal_user vsz_limit = 18446744073709551615 B } service doveadm { chroot = client_limit = 1 drop_priv_before_exec = no executable = doveadm-server extra_groups = group = idle_kill = 0 privileged_group = process_limit = 0 process_min_avail = 0 protocol = service_count = 1 type = unix_listener doveadm-server { group = mode = 0600 user = } user = vsz_limit = 18446744073709551615 B } service imap-login { chroot = login client_limit = 0 drop_priv_before_exec = no executable = imap-login extra_groups = group = idle_kill = 0 inet_listener imap { address = port = 143 ssl = no } inet_listener imaps { address = port = 993 ssl = yes } privileged_group = process_limit = 0 process_min_avail = 0 protocol = imap service_count = 1 type = login user = $default_login_user vsz_limit = 64 M } service imap { chroot = client_limit = 1 drop_priv_before_exec = no executable = imap extra_groups = group = idle_kill = 0 privileged_group = process_limit = 1024 process_min_avail = 0 protocol = imap service_count = 1 type = unix_listener login/imap { group = mode = 0666 user = } user = vsz_limit = 18446744073709551615 B } service lmtp { chroot = client_limit = 0 drop_priv_before_exec = no executable = lmtp extra_groups = group = idle_kill = 0 privileged_group = process_limit = 0 process_min_avail = 0 protocol = lmtp service_count = 0 type = unix_listener lmtp { group = mode = 0666 user = } user = vsz_limit = 0 } service log { chroot = client_limit = 0 drop_priv_before_exec = no executable = log extra_groups = group = idle_kill = 0 privileged_group = process_limit = 1 process_min_avail = 0 protocol = service_count = 0 type = log user = vsz_limit = 18446744073709551615 B } service managesieve-login { chroot = login client_limit = 0 drop_priv_before_exec = no executable = managesieve-login extra_groups = group = idle_kill = 0 inet_listener sieve { address = port = 4190 ssl = no } privileged_group = process_limit = 0 process_min_avail = 0 protocol = sieve service_count = 1 type = login user = $default_login_user vsz_limit = 64 M } service managesieve { chroot = client_limit = 1 drop_priv_before_exec = no executable = managesieve extra_groups = group = idle_kill = 0 privileged_group = process_limit = 0 process_min_avail = 0 protocol = sieve service_count = 1 type = unix_listener login/sieve { group = mode = 0666 user = } user = vsz_limit = 18446744073709551615 B } service pop3-login { chroot = login client_limit = 0 drop_priv_before_exec = no executable = pop3-login extra_groups = group = idle_kill = 0 inet_listener pop3 { address = port = 110 ssl = no } inet_listener pop3s { address = port = 995 ssl = yes } privileged_group = process_limit = 0 process_min_avail = 0 protocol = pop3 service_count = 1 type = login user = $default_login_user vsz_limit = 64 M } service pop3 { chroot = client_limit = 1 drop_priv_before_exec = no executable = pop3 extra_groups = group = idle_kill = 0 privileged_group = process_limit = 1024 process_min_avail = 0 protocol = pop3 service_count = 1 type = unix_listener login/pop3 { group = mode = 0666 user = } user = vsz_limit = 18446744073709551615 B } service ssl-params { chroot = client_limit = 0 drop_priv_before_exec = no executable = ssl-params extra_groups = group = idle_kill = 0 privileged_group = process_limit = 0 process_min_avail = 0 protocol = service_count = 0 type = startup unix_listener login/ssl-params { group = mode = 0666 user = } unix_listener ssl-params { group = mode = 0666 user = } user = vsz_limit = 18446744073709551615 B } service tcpwrap { chroot = client_limit = 1 drop_priv_before_exec = no executable = tcpwrap extra_groups = group = idle_kill = 0 privileged_group = process_limit = 0 process_min_avail = 0 protocol = service_count = 0 type = user = $default_internal_user vsz_limit = 18446744073709551615 B } shutdown_clients = yes ssl = yes ssl_ca = ssl_cert = </etc/nginx/ssl/wildcard.domain.net_bundle.crt ssl_cert_username_field = commonName ssl_cipher_list = ALL:!LOW:!SSLv2:!EXP:!aNULL ssl_dh_parameters_length = 1024 ssl_key = </etc/nginx/ssl/wildcard.domain.net.key ssl_key_password = ssl_parameters_file = ssl-parameters.dat ssl_parameters_regenerate = 0 ssl_protocols = !SSLv2 !SSLv3 ssl_verify_client_cert = no syslog_facility = mail userdb { args = /etc/dovecot/dovecot-sql.conf.ext driver = sql } valid_chroot_dirs = verbose_auth = no verbose_proctitle = no verbose_ssl = no version_ignore = no protocol lmtp { mail_plugins = } protocol lda { mail_plugins = } protocol imap { imap_id_log = * } Thank you!

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