March 2017 - dovecot - dovecot.org

dsync replication
by George Dimakopoulos 31 Mar '17

31 Mar '17

Is it stable for dovecot 2.2.27 to implement DRBD (or HAST) on block level for maildir data replication instead of using dsync plugin? Regards, George

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Slow performance with large folders over the Internet
by Shawn Heisey 31 Mar '17

31 Mar '17

Dovecot package version is 1:1.2.15-7+deb6u1. It is in Debian 6.0.10, using the Debian package. The server is in my basement at home, and is exposed to the Internet so I can fully access my mail from anywhere. I use IMAP for reading mail. I have a number of folders in my mailbox that have thousands of messages in them, from mailing lists. When I'm at home, I have a LAN connection to the server. It goes through a Cisco firewall that limits the connection speed to 100Mb/s. In this situation, I can open a folder with 25000 messages in it, click on the next unread message that Thunderbird did not know about before, and within a second or two, the message will download, allowing me to view it and reply. When I'm at work, with highly variable network latency between Thunderbird and the server, doing exactly the same thing takes a LOT longer. I have seen it take as long as 15 minutes for a single message. If I open a folder with only a few messages in it, it is fast. The server is not overloaded -- I can log into it with ssh and use "mutt -f" to open a folder directly. Loading thousands of messages into mutt takes a while, but I have no difficulty using the ssh connection and running commandline programs. This suggests that the IMAP communication between the server and the client involves a large amount of back and forth communication when the message count in the folder is high, possibly something for every message in the folder. It happens quickly on a LAN but crawls on a connection with high latency. I can understand it taking a few seconds longer on a high-latency link, but it takes minutes. I do plan on building a new server and migrating to Dovecot 2.x, but I haven't had the time to work on that. Is this a known problem? If so, is it fixed in 2.x? Thanks, Shawn

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Studying dovecot source code (searching for mail_deliver_hook_set)
by chaouche yacine 30 Mar '17

30 Mar '17

Hello dovecot, I would like to study how dovecot manages quota, especially how it deals with the maildirsize file if one chooses to implement quota according to the maildir++ specification. I made a number of assumptions : 1. mail is (always/sometimes) delivered with the dovecot-lda binary, which source code is in src/lda. 2. mail is sent with the mail_deliver function which is called from src/lda/main.c and is defined in src/lib-lda/mail-deliver.c 3. mail_deliver function calls the deliver_mail function (it seems to be pointer to a function) 4. according to src/lib-lda/mail-deliver.h, deliver_mail is set with the mail_deliver_hook_set function. Here's what the comment says /* Sets the deliver_mail hook and returns the previous hook, which the new_hook should call if it's non-NULL. */ deliver_mail_func_t *mail_deliver_hook_set(deliver_mail_func_t *new_hook); The problem at this point is that I can't find where is this function called. A grep on the sources only reveals two results : -*- mode: grep; default-directory: "~/DOWNLOADS/APPS/dovecot-2.2.13/src/" -*- Grep started at Tue Mar 28 17:01:50 grep -nH -e 'mail_deliver_hook_set' -r . ./lib-lda/mail-deliver.c:428:deliver_mail_func_t *mail_deliver_hook_set(deliver_mail_func_t *new_hook) ./lib-lda/mail-deliver.h:103:deliver_mail_func_t *mail_deliver_hook_set(deliver_mail_func_t *new_hook); Grep finished (matches found) at Tue Mar 28 17:01:50 According to the changelog this function has been introduced back in 2010. I don't know if it's really used ? * I am working on the 2.2.13 sources because that's what's installed on my server. * I couldn't find a developers mailling listed in http://www.dovecot.org/mailinglists.html so I'm just posting this here. -- Yassine.

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Email Push to Iphone
by mca＠caloro.ch 30 Mar '17

30 Mar '17

Hello Please exist in Dovecot 2.2.13 the E-Mail Push function? So that the Email on me Iphone are available at this moment that will be transfered, I see or found any other 3part software "Z-push", but it's this function are not included on dovecot? Thanks and regards Mauri

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Using SpamProbe via only sieve scripts
by Mark Constable 30 Mar '17

30 Mar '17

FWIW this took me days to get right, and still needs tinkering, but it might make for a good starting point for anyone else needing something similar (ie; I don't use or need the overhead of spamassassin or rspamd). https://gist.github.com/markc/eeeb66ce30ea805af62631656cf86c4d Any comments or corrections on that page would be appreciated.

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Re: cannot login to imap under load
by Gerard Ranke 29 Mar '17

29 Mar '17

Hi Maria, It does indeed run from systemd, so this is what's currently in the dovecot unit file ( /etc/systemd/system/dovecot.service ): [Unit] Description=Dovecot IMAP/POP3 email server After=local-fs.target network.target [Service] Type=simple ExecStart=/usr/sbin/dovecot -F NonBlocking=yes TasksMax=10000 LIMIT_NOFILE=10000 [Install] WantedBy=multi-user.target Unfortunately, it doesn't seem to work... Best, gerard On 29-03-17 13:13, María Arrea wrote: > > If you are running dovecot via systemd, increase NOFILES in the > dovecot startup script > > El 29/03/17 a las 13:07, Gerard Ranke escribió: >> Hi Steffen, >> >> On 29-03-17 12:38, Steffen Kaiser wrote: >>> On Tue, 28 Mar 2017, Gerard Ranke wrote: >>> >>>> dovecot: master: Error: service(imap): fork() failed: Resource >>>> temporarily unavailable >>>> dovecot: master: Error: service(imap): command startup failed, >>>> throttling for 2 secs >>> check out the ulimits for the Dovecot process. >>> >>> -- Steffen Kaiser >> Here they are: >> >> dovecot@mail:~> ulimit -a >> core file size (blocks, -c) 0 >> data seg size (kbytes, -d) unlimited >> scheduling priority (-e) 0 >> file size (blocks, -f) unlimited >> pending signals (-i) 256942 >> max locked memory (kbytes, -l) 64 >> max memory size (kbytes, -m) unlimited >> open files (-n) 10000 >> pipe size (512 bytes, -p) 8 >> POSIX message queues (bytes, -q) 819200 >> real-time priority (-r) 0 >> stack size (kbytes, -s) 8192 >> cpu time (seconds, -t) unlimited >> max user processes (-u) 256942 >> virtual memory (kbytes, -v) unlimited >> file locks (-x) unlimited >> >> This looks ok to me, but on startup, I still get: >> >> dovecot[9309]: Warning: fd limit (ulimit -n) is lower than required >> under max. load (1024 < 10000), because of service auth { client_limit } >> >> Strange thing is that dovecot still complains about the fd limit being >> 1024, while I set it to 10000. And how can a ulimit be too low 'because >> of service auth'? I don't get that at all. Thanks for your interest! >> >> gerard > >

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cannot login to imap under load
by Gerard Ranke 29 Mar '17

29 Mar '17

Dear list, We moved our dovecot installation to a new vm, and ever since there are problems logging in to our imap server during office hours. ( Evenings and weekends are fine. ) Both the new and the old machine are dovecot 2.2.13. Symptoms: Logging in via imap gives: . OK Pre-login capabilities listed, post-login capabilities have more. a login <loginname> <passwd> * OK Waiting for authentication master process to respond.. closed whereas using the same credentials with pop3: +OK Dovecot ready. user <loginname> +OK pass <passwd> +OK Logged in. Our mail.err log gives lots of: dovecot: imap-login: Error: master(imap): Auth request timed out (received 0/12 bytes) dovecot: imap: Error: Login client disconnected too early dovecot: auth: Error: Master request 24000.918 not found dovecot: master: Error: service(imap): fork() failed: Resource temporarily unavailable dovecot: master: Error: service(imap): command startup failed, throttling for 2 secs Note thate we our users almost exclusively use imap. Normally we would have some 7 or 800 imap processes running and only a few pop3. Our doveconf -n output: # 2.2.13: /etc/dovecot/dovecot.conf # OS: Linux 4.4.38-93-default x86_64 SUSE Linux Enterprise Server 12 (x86_64) auth_mechanisms = plain login default_client_limit = 2000 default_process_limit = 2000 default_vsz_limit = 512 M disable_plaintext_auth = no imap_client_workarounds = tb-extra-mailbox-sep import_environment = TZ DEBUG_OUTOFMEM DOVECOT_HOSTDOMAIN mail_location = maildir:~/Maildir mail_plugins = " quota" 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 ihave namespace inbox { inbox = yes location = 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 = } passdb { args = /etc/dovecot/dovecot-ldap.conf.ext driver = ldap } plugin { quota = maildir:User quota quota_rule = *:storage=1G quota_rule2 = Trash:storage=+10%% sieve = ~/.dovecot.sieve sieve_dir = ~/sieve } protocols = imap pop3 lmtp sieve service anvil { client_limit = 8003 } service auth { client_limit = 10000 unix_listener /var/spool/postfix/private/auth { group = postfix mode = 0660 user = postfix } unix_listener auth-userdb { group = dovecot mode = 0666 } } service imap-login { inet_listener imap { port = 143 } inet_listener imaps { port = 993 ssl = yes } process_min_avail = 4 service_count = 0 } service imap { process_limit = 2048 } service pop3-login { inet_listener pop3 { port = 110 } inet_listener pop3s { port = 995 ssl = yes } process_min_avail = 4 service_count = 0 } service pop3 { process_limit = 2048 } ssl_cert = </etc/ssl/certs/hkuwildcardthawte.crt ssl_key = </etc/ssl/certs/hkuwildcardthawte.key ssl_protocols = !SSLv2 !SSLv3 userdb { args = /etc/dovecot/dovecot-ldap-userdb.conf driver = ldap } protocol lmtp { mail_plugins = " quota sieve" } protocol lda { mail_plugins = " quota sieve" } protocol imap { mail_max_userip_connections = 10 mail_plugins = " quota imap_quota" } Thank you all for any insight, it will be much appreciated! Best regards, gerard

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pigeonhole / vacation
by A. Schulze 29 Mar '17

29 Mar '17

Hello, we use the sieve vacation module to answer messages for certain mailboxes. vacation send back answers to most but not all messages wich is fine and intended. .dovecot.sieve looks like this: require ["vacation", "variables"]; if header :matches "subject" "*" { vacation :subject "Automatic response to: ${1}" "thanks for your message"; keep; } But now I would like to distinct messages that where answered from those where the vacation module did not send back a message. Is it possible to store answered messages in one folder and unanswered in an other? # probably invalid sieve syntax if vacation .... { fileinto "answered/"; stop; else fileinto "unanswered/"; stop; } After reading RFC 5230 I feel it's not possible at all :-/ Andreas

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Re: Email Push to Iphone
by Ricardo Branco 29 Mar '17

29 Mar '17

there is this plugin to use APNS to notify phones, its a faf though as you need a legal OSX Server to generate the signing keys, I never ended up implementing it. https://github.com/st3fan/dovecot-xaps-daemon Aki Tuomi wrote on 29/03/2017 07:29: > > On 29.03.2017 07:24, mca(a)caloro.ch wrote: >> Hello >> >> >> >> Please exist in Dovecot 2.2.13 the E-Mail Push function? >> >> >> >> So that the Email on me Iphone are available at this moment that will be >> transfered, I see or found any other 3part software "Z-push", but it's this >> function are not included on dovecot? >> >> >> >> Thanks and regards >> >> Mauri >> >> > There exists a push notification framework for dovecot, but it does not support iPhone push directly. See https://wiki2.dovecot.org/Plugins/PushNotification > > Aki

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Tip: update dovecot MD5 password from PAM
by Steinar Bang 29 Mar '17

29 Mar '17

This is a PAM module that listens for password changes, and will update the MD5 password for a user, in a file that dovecot can read, when the user's password is changed: https://github.com/steinarb/pam_dovecotmd5pwd Caveat emptor! (Works for me...! :-) )

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