- dovecot - dovecot.org

IMAP dovecot\postgres low authentication performance
by Anatoliy Zhestov 19 Feb '25

19 Feb '25

Hi. We have a performance problem with imap authentication through postgresql. Our servers(modoboa based) have a big amount of permanent imap connections(5000-50000). Current performance is about 3000 successful authentications per hour. No visible reasons for such low speed. Accordingly, after a network failure or server restart, all clients try to reconnect, but restoring the connection pool takes hours and even tens of hours. Judging by the logs after the restart, a huge number of auth requests closed by timeout after 70-90 seconds. The postgresql database is not overloaded at the restore connections process and the postgresql connection pool (100) does not overflow. Manually started sql auth queries work fast, tables have indexes. So I guess there is a bottleneck somewhere in dovecot auth service or postgresql driver. I couldn't find any settings in the documentation that are directly responsible for regulating the number of connections to PostgreSQL from the auth service or performance of the driver. Is there any way to manage this? Does it make sense to use pgbouncer in front of the base? What else can be a bottleneck in our configuration and how to regulate the number of possible simultaneous authentications via PostgreSQL? I would be happy for any advice on how to increase the performance to at least 100 authentications per second. Thanks in advance for your help. Anatoliy Zhestov. ---------------- configs of server with 48 core, 184 gb mem --------------- dovecot 2.3.16 # 2.3.16 (7e2e900c1a): /etc/dovecot/dovecot.conf # Pigeonhole version 0.5.16 (09c29328) # OS: Linux 5.15.0-126-generic x86_64 Ubuntu 22.04.5 LTS # Hostname: imap.ourcompany.net auth_cache_negative_ttl = 0 auth_cache_size = 20 M auth_cache_ttl = 3 hours auth_master_user_separator = * auth_mechanisms = plain login default_client_limit = 131072 default_process_limit = 131072 dict { quota = pgsql:/etc/dovecot/dovecot-dict-sql.conf.ext } 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 mai lbox date index ihave duplicate mime foreverypart extracttext editheader imapflags notify vnd.dovecot.pipe vnd.dovecot.execute namespace inbox { inbox = yes location = mailbox Drafts { auto = subscribe special_use = \Drafts } mailbox Junk { auto = subscribe special_use = \Junk } mailbox Sent { auto = subscribe special_use = \Sent } mailbox Trash { auto = subscribe special_use = \Trash } prefix = } passdb { args = /etc/dovecot/dovecot-sql.conf.ext driver = sql } passdb { args = /etc/dovecot/dovecot-sql-master.conf.ext driver = sql master = yes pass = yes } plugin { quota = dict:User quota::proxy::quota sieve = ~/.dovecot.sieve sieve_dir = ~/sieve sieve_execute_bin_dir = /usr/lib/dovecot/sieve-execute sieve_execute_socket_dir = . sieve_extensions = +notify +imapflags +editheader +body +vnd.dovecot.execute +vnd.dovecot.pipe sieve_pipe_bin_dir = /usr/lib/dovecot/sieve-execute sieve_pipe_socket_dir = . sieve_plugins = sieve_extprograms } protocols = " imap lmtp sieve" service anvil { client_limit = 393219 } service auth { client_limit = 524288 unix_listener /var/spool/postfix/private/auth { group = postfix mode = 0666 user = postfix } unix_listener auth-radicale { group = radicale mode = 0666 user = radicale } unix_listener auth-userdb { user = vmail } } service config { vsz_limit = 1 G } service dict { unix_listener dict { mode = 0600 user = vmail } } service imap { executable = imap postlogin process_limit = 131072 vsz_limit = 1 G } service lmtp { unix_listener /var/spool/postfix/private/dovecot-lmtp { group = postfix mode = 0600 user = postfix } vsz_limit = 512 M } service pop3 { executable = pop3 postlogin } service postlogin { executable = script-login /usr/local/bin/postlogin.sh service_count = 1000 process_min_avail = 5 user = modoboa } service send-to-click-frontapp1 { executable = script /usr/lib/dovecot/sieve-execute/clickhouse_log_frontapp1.sh unix_listener send-to-click-frontapp1 { group = vmail mode = 0666 user = vmail } user = dovenull vsz_limit = 2 G } service send-to-click { executable = script /usr/lib/dovecot/sieve-execute/clickhouse_log.sh unix_listener send-to-click { group = vmail mode = 0666 user = vmail } user = dovenull vsz_limit = 2 G } service stats { unix_listener stats-reader { group = vmail mode = 0660 user = vmail } unix_listener stats-writer { group = vmail mode = 0660 user = vmail } vsz_limit = 2 G } ssl_cert = </etc/letsencrypt/live/imap.ourcompany.net/fullchain.pem ssl_cipher_list = EECDH+ECDSA+AESGCM:EECDH+aRSA+AESGCM:EECDH+ECDSA+SHA384:EECDH+ECDSA+SHA256:EECDH+aRSA+SHA384:EECDH+aRSA+SHA256:EECDH+aRSA+RC4:EECDH:EDH+aRSA:!aNULL:!eNULL:!LOW:!3DES:!MD5:!EXP:!PSK:!SRP:!DSS:!RC4 ssl_client_ca_dir = /etc/ssl/certs ssl_dh = # hidden, use -P to show it ssl_key = # hidden, use -P to show it ssl_min_protocol = TLSv1 stats_writer_socket_path = userdb { driver = prefetch } userdb { args = /etc/dovecot/dovecot-sql.conf.ext driver = sql } protocol lmtp { mail_plugins = quota sieve postmaster_address = postmaster(a)imap.ourcompany.net } protocol imap { mail_max_userip_connections = 50 mail_plugins = quota imap_quota } /etc/dovecot/dovecot-sql-master.conf.ex driver = pgsql connect = host=127.0.0.1 port=5432 dbname=modoboa user=modoboa password=XXXXXXXXXXXXXXXXX password_query = SELECT email AS user, password FROM core_user WHERE email='%u' and is_active and master_user /etc/dovecot/dovecot-sql.conf.ext driver = pgsql connect = host=127.0.0.1 port=5432 dbname=modoboa user=modoboa password=XXXXXXXXXXXXXXXXX user_query = SELECT '/srv/vmail/%d/%n' AS home, 1003 as uid, 1003 as gid, '*:bytes=' || mb.quota || 'M' AS quota_rule FROM admin_mailbox mb INNER JOIN admin_domain dom ON mb.domain_id=dom.id INNER JOIN core_user u ON u.id=mb.user_id WHERE (mb.is_send_only IS NOT TRUE OR '%s' NOT IN ('imap', 'pop3', 'lmtp')) AND mb.address='%n' AND dom.name='%d' password_query = SELECT email AS user, password, '/srv/vmail/%d/%n' AS userdb_home, 1003 AS userdb_uid, 1003 AS userdb_gid, CONCAT('*:bytes=', mb.quota, 'M') AS userdb_quota_rule FROM core_user u INNER JOIN admin_mailbox mb ON u.id=mb.user_id INNER JOIN admin_domain dom ON mb.domain_id=dom.id WHERE (mb.is_send_only IS NOT TRUE OR '%s' NOT IN ('imap', 'pop3')) AND email='%u' AND is_active AND dom.enabled iterate_query = SELECT email AS user FROM core_user /usr/local/bin/postlogin.sh #!/bin/sh PATH="/usr/bin:/usr/local/bin:/bin" psql -c "UPDATE core_user SET last_login=now() WHERE username='$USER'" > /dev/null exec "$@" /usr/lib/dovecot/sieve-execute/clickhouse_log_frontapp1.sh #!/bin/bash cd /tmp logger -i -t SIEVE_TEST "$1,$2,$3,$4" clickhouse-client -h XXXXXXXXXXXXXXXXX -d default -u some_user --password XXXXXXXXXXXXXXXXX \ --param_origin_from="$1" \ --param_origin_to="$2" \ --param_message_id="$3" \ --param_forward="$4" \ -q "INSERT INTO frontapp1_redirects (origin_from_email,origin_to_email,message_id,forward_email) VALUES ({origin_from:String},{origin_to:String},{message_id:String},{forward:String})" /usr/lib/dovecot/sieve-execute/clickhouse_log.sh #!/bin/bash cd /tmp logger -i -t SIEVE_TEST "$1,$2,$3,$4" clickhouse-client -h XXXXXXXXXXXXXXXXX -d default -u some_user --password XXXXXXXXXXXXXXXXX \ --param_origin_from="$1" \ --param_origin_to="$2" \ --param_message_id="$3" \ --param_forward="$4" \ -q "INSERT INTO frontapp_redirects (origin_from_email,origin_to_email,message_id,forward_email) VALUES ({origin_from:String},{origin_to:String},{message_id:String},{forward:String})"

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auth_userdb_iterate
by Luigi Trovato 19 Feb '25

19 Feb '25

Hello, I have a doubt: is the lua function "auth_userdb_iterate" expected to always return the whole list of users no matter what, or it should evaluate if a specific virtual domain is provided as req argument and only list the users in that specific domain? And should the returned user list be in the format "username(a)domain.tld" or "username" ? -- Ciao, Luigi

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lua API and returning reason and CONTACTADMIN
by Arkadiusz Miśkiewicz 19 Feb '25

19 Feb '25

Hello. Trying to pass reason response via lua by passing it at dovecot.auth.PASSDB_RESULT_USER_DISABLED like: function auth_password_verify(request, password) return dovecot.auth.PASSDB_RESULT_USER_DISABLED, "reason=custom_message" end function auth_userdb_lookup(request) return dovecot.auth.PASSDB_RESULT_OK, "uid=428671 gid=9726 home=/var/mail/existusertest" end function script_init() return 0 end function script_deinit() end Unfortunately returned result contains no custom message and also returns AUTHENTICATIONFAILED instead of CONTACTADMIN: NO [AUTHENTICATIONFAILED] Authentication failed. while I would expect something like: NO [CONTACTADMIN] custom_message: Any reason for such behaviour and how to get reason passed and proper CONTACTADMIN? Tests done on 2.3.21.1. passdb { driver = lua mechanisms = login plain args = file=/etc/dovecot/lua_auth_script_test_fail.lua blocking=yes } userdb { driver = lua args = file=/etc/dovecot/lua_auth_script_test_fail.lua blocking=yes } -- Arkadiusz Miśkiewicz, arekm / ( maven.pl | pld-linux.org )

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Can someone explain this to me, please?
by Ken Wright 19 Feb '25

19 Feb '25

The last time I checked my mail.log I found the following line: 2025-02-18T22:41:31.175798-05:00 grace dovecot: imap-login: Login aborted: Connection closed (auth failed, 1 attempts in 8 secs) (auth_failed): user=<wizard(a)koalatyworks.com>, method=PLAIN, rip=192.168.1.1, lip=192.168.1.10, TLS, session=<wTMBiHYu5pXAqAEB> Is this a password error or something more? Ken

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Doveadm Backup
by Doug Hardie 18 Feb '25

18 Feb '25

I tried the backup again tonight. I am now getting a new error: mail# doveadm backup -f -u doug remote:checkout dsync-remote(doug)<1c8BDo4xtGe74wAA+dxtXQ>: Warning: Deleting mailbox 'INBOX': UID=92440 GUID=1465118975.V4eI7cfa32M232845.mail is missing locally dsync-remote(doug)<1c8BDo4xtGe74wAA+dxtXQ>: Error: Couldn't delete mailbox INBOX: INBOX can't be deleted. dsync-local(doug)<N0q9NI0xtGf4vgAAZU03Dg>: Error: Remote command returned error 65: ssh checkout doveadm dsync-server -udoug -U Anytime I run it now generates the same error messages. However on the backup machine the .cur directory is empty. I presume that is the INBOX referred to in the messages. All the other directories appear to be intact. -- Doug

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2.4.0: managesieve: sieve_script_path setting variables: Unknown variable 'user'
by Bjoern Franke 18 Feb '25

18 Feb '25

Hi, I have the following (manage)sieve-related parts in my 2.4.0 config: within the namespace inbox: mailbox Junk { auto = subscribe autoexpunge = 14d sieve_script junk { type = before cause = copy driver = file path = /data/mail/sieve/report-spam.sieve } special_use { "\Junk" = yes } service managesieve-login { inet_listener sieve { port = 4190 } } service managesieve { } sieve_script personal { active_path = /data/mail/%{user}/dovecot.sieve driver = file path = /data/mail/%{user}/sieve } Accessing via managesieve fails: Error: sieve: file storage: sieve_file_storage settings: Failed to parse configuration: Failed to expand sieve_script_path setting variables: Unknown variable 'user' But the sieve rules in general work. Regards Bjoern

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Re: Userdb lookup problems
by Ken Wright 18 Feb '25

18 Feb '25

On Mon, 2025-02-17 at 15:49 +0200, Timo Sirainen wrote: > On 16. Feb 2025, at 17.03, Ken Wright via dovecot > <dovecot(a)dovecot.org> wrote: > > mysql localhost { > > user = something > > password = MYPASSWORD > > dbname = something > > } > .. > > According to the logs, Dovecot isn't trying to connect using the > > user > > something, it's using the user dovecot. That's not the user for > > the > > database. > > The default mysql user is empty, not "dovecot". So it must be getting > "dovecot" user from somewhere in your config. Look at your "doveconf" > output - maybe the mysql_user gets overridden in some other config > file. Things to look at: > > doveconf mysql > doveconf | grep mysql > doveconf I went through every file in conf.d trying to find a mention of dovecot with no positive results. Then I tried the three things to look at you suggested, and got this: doveconf mysql: mysql localhost { dbname = database password = # hidden, use -P to show it user = DBuser } doveconf | grep mysql: sql_driver = mysql mysql localhost { doveconf: # 2.4.0-2+ubuntu24.04 (daeb6bc59c): /etc/dovecot/dovecot.conf # Pigeonhole version 2.4.0-2+ubuntu24.04 (1b2d5bb9) # OS: Linux 6.8.0-53-generic x86_64 Ubuntu 24.04.2 LTS ext4 # Hostname: localhost dovecot_config_version = 2.4.0 auth_mechanisms = auth_mechanisms { plain = yes login = yes } dovecot_storage_version = 2.4.0 mail_driver = maildir mail_gid = vmail mail_inbox_path = /var/vmail/%{user | domain}/%{user | username } mail_path = /var/vmail/%{user | domain }/%{user | username }/Maildir mail_uid = vmail mailbox_list_utf8 = yes passdb_default_password_scheme = ARGON2I protocols = protocols { imap = yes lmtp = yes sieve = yes } sql_driver = mysql ssl = required ssl_server { cert_file = /etc/letsencrypt/live/mailserver.example1.com/fullchain.pem key_file = /etc/letsencrypt/live/mailserver.example1.com/privkey.pem prefer_ciphers = server } namespace inbox { mailbox Drafts { auto = create special_use = special_use { "\\Drafts" = yes } } mailbox Junk { auto = create special_use = special_use { "\\Junk" = yes } } mailbox Trash { auto = create special_use = special_use { "\\Trash" = yes } } mailbox Sent { auto = create special_use = special_use { "\\Sent" = yes } } } service auth { unix_listener /var/spool/postfix/private/auth { group = postfix mode = 0600 user = postfix } } mysql localhost { dbname = database password = # hidden, use -P to show it user = DBuser } passdb sql { query = SELECT username AS username, domain, password FROM mailbox WHERE username = '%{user | username}' AND domain = '%{user | domain}' AND active= '1' } userdb sql { iterate_query = SELECT username AS username, domain FROM mailbox query = SELECT mail_path, uid, gid FROM mailbox WHERE username = '%{user | username}' AND domain = '%{user | domain}' AND active= '1' } local 127.0.0.1 { local_name mailserver.example1.com { protocol imap { ssl_server { cert_file = /etc/letsencrypt/live/mailserver.example1.com/fullchain.pem key_file = /etc/letsencrypt/live/mailserver.example1.com/privkey.pem } } } local_name mail.example2.net { protocol imap { ssl_server { cert_file = /etc/letsencrypt/live/mail.example2.net/fullchain.pem key_file = /etc/letsencrypt/live/mail.example2.net/privkey.pem } } } } I can't find anything indicating a database user 'dovecot.' Would you like to see the results of tail /var/log/mail.log? Ken On Mon, 2025-02-17 at 15:49 +0200, Timo Sirainen wrote: On 16. Feb 2025, at 17.03, Ken Wright via dovecot <dovecot(a)dovecot.org> wrote: mysql localhost { user = something password = MYPASSWORD dbname = something } .. According to the logs, Dovecot isn't trying to connect using the user something, it's using the user dovecot. That's not the user for the database. The default mysql user is empty, not "dovecot". So it must be getting "dovecot" user from somewhere in your config. Look at your "doveconf" output - maybe the mysql_user gets overridden in some other config file. Things to look at: doveconf mysql doveconf | grep mysql doveconf I went through every file in conf.d trying to find a mention of dovecot with no positive results. Then I tried the three things to look at you suggested, and got this: doveconf mysql: mysql localhost { dbname = database password = # hidden, use -P to show it user = DBuser } doveconf | grep mysql: sql_driver = mysql mysql localhost { doveconf: # 2.4.0-2+ubuntu24.04 (daeb6bc59c): /etc/dovecot/dovecot.conf # Pigeonhole version 2.4.0-2+ubuntu24.04 (1b2d5bb9) # OS: Linux 6.8.0-53-generic x86_64 Ubuntu 24.04.2 LTS ext4 # Hostname: localhost dovecot_config_version = 2.4.0 auth_mechanisms = auth_mechanisms { plain = yes login = yes } dovecot_storage_version = 2.4.0 mail_driver = maildir mail_gid = vmail mail_inbox_path = /var/vmail/%{user | domain}/%{user | username } mail_path = /var/vmail/%{user | domain }/%{user | username }/Maildir mail_uid = vmail mailbox_list_utf8 = yes passdb_default_password_scheme = ARGON2I protocols = protocols { imap = yes lmtp = yes sieve = yes } sql_driver = mysql ssl = required ssl_server { cert_file = /etc/letsencrypt/live/mailserver.example1.com/fullchain.pem key_file = /etc/letsencrypt/live/mailserver.example1.com/privkey.pem prefer_ciphers = server } namespace inbox { mailbox Drafts { auto = create special_use = special_use { "\\Drafts" = yes } } mailbox Junk { auto = create special_use = special_use { "\\Junk" = yes } } mailbox Trash { auto = create special_use = special_use { "\\Trash" = yes } } mailbox Sent { auto = create special_use = special_use { "\\Sent" = yes } } } service auth { unix_listener /var/spool/postfix/private/auth { group = postfix mode = 0600 user = postfix } } mysql localhost { dbname = database password = # hidden, use -P to show it user = DBuser } passdb sql { query = SELECT username AS username, domain, password FROM mailbox WHERE username = '%{user | username}' AND domain = '%{user | domain}' AND active= '1' } userdb sql { iterate_query = SELECT username AS username, domain FROM mailbox query = SELECT mail_path, uid, gid FROM mailbox WHERE username = '%{user | username}' AND domain = '%{user | domain}' AND active= '1' } local 127.0.0.1 { local_name mailserver.example1.com { protocol imap { ssl_server { cert_file = /etc/letsencrypt/live/mailserver.example1.com/fullchain.pem key_file = /etc/letsencrypt/live/mailserver.example1.com/privkey.pem } } } local_name mail.example2.net { protocol imap { ssl_server { cert_file = /etc/letsencrypt/live/mail.example2.net/fullchain.pem key_file = /etc/letsencrypt/live/mail.example2.net/privkey.pem } } } } I can't find anything indicating a database user 'dovecot.' Would you like to see the results of tail /var/log/mail.log? Ken

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Doveadm Backup
by Doug Hardie 18 Feb '25

18 Feb '25

I am using doveadm backup to backup the mail server's files for a specific user. This is a test environment for the backup machine. All it does is sit there until I run backup on the mail server. However, I am encountering an issue occasionally where backup throws the following message: Warning: Deleting mailbox 'Deleted Messages': UID=533920 already exists locally for a different mail: GUIDs don't match (1739791386.M526904P56414.checkout,S=2206,W=2264 vs 1739674845.M569094P6598.mail,S=6530202,W=6615064) At this point it stops and the indicated mailbox has been deleted. It is not always the same mailbox. I then have to run the backup again and wait for it to download the entire directory which takes a long time. I was hoping to use this approach for a frequently run backup, but it appears it is not feasible. Some mailboxes are large enough that a second backup would be initiated before the complete reload had completed. Can this be corrected? -- Doug

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Question about push notification plugin
by Zakaria 17 Feb '25

17 Feb '25

Hi Dovecot Mailing List members, I just struggled to understand the plugin events and wondered if anyone can help on this. I wanted to capture the event when I mark message as not spam move event as well as when I move message to new folder event, I found MessageNew and MessageAppend, and couldnt figure out which one is responsible of the relevant event? Also, feedback to the dovecot dev team, it would great if we have push notification redis driver. Thanks in advance. Zakaria.

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Re: Doveadm Backup Error
by Asai 17 Feb '25

17 Feb '25

Thank you, Timo, that fixed the problem. Asai On 2/17/2025 9:03 AM, Timo Sirainen wrote: > On 17. Feb 2025, at 16.26, Asai via dovecot <dovecot(a)dovecot.org> wrote: >> >> sieve_script personal { >> active_path = /vmail/%{user | domain }/%{user | username >> }/home/.dovecot.sieve >> driver = file >> path = /vmail/%{user | domain }/%{user | username }/home/sieve >> } > > Looks like %variables aren't really working right with Sieve / doveadm > combination. It gives an error: > > Error: sieve: sieve_file_storage settings: Failed to parse > configuration: Failed to expand sieve_script_path setting variables: > Unknown variable 'user' > > So for now the only way is to avoid %variables there - that simplifies > the config anyway: > > sieve_script personal { > active_path = ~/.dovecot.sieve > path = ~/sieve > } > Thank you, Timo, that fixed the problem. Asai On 2/17/2025 9:03 AM, Timo Sirainen wrote: On 17. Feb 2025, at 16.26, Asai via dovecot <dovecot(a)dovecot.org> wrote: sieve_script personal { active_path = /vmail/%{user | domain }/%{user | username }/ home/.dovecot.sieve driver = file path = /vmail/%{user | domain }/%{user | username }/home/sieve } Looks like %variables aren't really working right with Sieve / doveadm combination. It gives an error: Error: sieve: sieve_file_storage settings: Failed to parse configuration: Failed to expand sieve_script_path setting variables: Unknown variable 'user' So for now the only way is to avoid %variables there - that simplifies the config anyway: sieve_script personal { active_path = ~/.dovecot.sieve path = ~/sieve }

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