- dovecot - dovecot.org

Multiple A Records for IMAP service
by Vijay Rajah 29 Aug '14

29 Aug '14

Hello All, I have a quick question. I have 2 MX servers each with a Dovecot Instances (2.2.6). These 2 Dovecot Instances are replicated by using Dsync... All works well. The questions is, Can I have 2 A records for my imap.mydomain.tld? The Idea being, if for any reason, one of the Dovecot IMAP instances are unreachable, the client can connect to the other Instance. (this is purely a fail over scenario). If it matters, The clients are Thunderbird, Android Native (default) Mail client, iOS Mail Client. -Thanks in advance Vijay

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Re: About Dovecot cluster and filesystems...
by Listas＠Adminlinux 29 Aug '14

29 Aug '14

Thank you Andreas!! > If you keep two separate storage areas you will have to figure out > how to sync them. But Dovecot Replication with dsync via tcp solves it. Right? Regards -- Thiago Henrique Em 29-08-2014 08:41, Andreas Kasenides escreveu: > This is what http://wiki2.dovecot.org/Director says. > If you keep two separate storage areas you will have to figure out how > to sync them. > And then make sure to keep the sync running smoothly and efficiently > without hick-ups. > Otherwise the potential exists that the users will see different things > upon login (at least temporarily). > > Andreas

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Documentation for /usr/lib/dovecot/imap executable
by Christoph Groth 29 Aug '14

29 Aug '14

Dear Dovecot experts, I'm in the process of setting up dovecot with mbsync as a local cache for remote IMAP servers. One recipe that I found involves using the /usr/lib/dovecot/imap (This is with Debian's dovecot package). For example, in .mbsyncrc I have IMAPAccount cwg-wf-local RequireSSL no Tunnel "/usr/lib/dovecot/imap -o mail_location=maildir:/home/cwg/.mail/cwg-wf" This works, but I wonder: is there any documentation for the /usr/lib/dovecot/imap executable? What options does it take? If there's no documentation: where can I find this command in dovecot's sources? Thank you, Christoph

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Postfix + dovecot setup
by Timothy Murphy 28 Aug '14

28 Aug '14

I'm trying to clarify the various ways in which I could set up Postfix + Dovecot + SpamAssassin under CentOS-7, and I'd welcome any comments on the following remarks. As far as I can see there are 3 standard ways of setting this up: 1. Use amavisd 2. Use dovecot + pigeonhole/sieve 3. Use spamass-milter At present I'm following (2), but am thinking of going over to (1), since this seems simpler. (Amavisd wasn't available when I set up CentOS-7, so I didn't consider it then.) It seems to me that (2) is using dovecot in a slightly odd way, since as far as I can see dovecot normally takes email from ~/Maildir/cur/ and then moves marked spam. I'm not quite sure if (3) is a genuine alternative, or if it is why it is not the standard? -- Timothy Murphy e-mail: gayleard /at/ eircom.net School of Mathematics, Trinity College, Dublin 2, Ireland

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About Dovecot cluster and filesystems...
by Listas＠Adminlinux 28 Aug '14

28 Aug '14

Hi all! Does dovecot cluster (with Proxy/Director) work only distributed filesystems (like NFS) ? Is Dovecot-replication + Ext4 recommended for production environments? Thanks! -- Thiago Henrique

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Dovecot Master User
by Clovis Tristao 28 Aug '14

28 Aug '14

Hi, I'm trying to use imapsync to migrate my accounts and mailbox (mbox) of an server A (Postfix + Dovecot) to a Server B (Zimbra), without having to change user passwords on the server A, using a master user account. I'm using this paper http://wiki2.dovecot.org/Authentication/MasterUsers as guidance. The Dovecot server A, is not letting me authenticate. Follow the testing and debug below: Testing: # telnet <ip_address> 8143 Trying <ip_address>... Connected to <ip_address>. Escape character is '^]'. * OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE AUTH=PLAIN] Dovecot ready. a login mailadm*masteruser masterpass a NO [AUTHENTICATIONFAILED] Authentication failed. b logout * BYE Logging out b OK Logout completed. Connection closed by foreign host. Debug: /var/log/maillog: Aug 28 10:29:51 centosVM dovecot: master: Dovecot v2.0.9 starting up (core dumps disabled) Aug 28 10:30:02 centosVM dovecot: auth: Debug: Loading modules from directory: /usr/lib64/dovecot/auth Aug 28 10:30:02 centosVM dovecot: auth: Debug: Module loaded: /usr/lib64/dovecot/auth/libauthdb_ldap.so Aug 28 10:30:02 centosVM dovecot: auth: Debug: Module loaded: /usr/lib64/dovecot/auth/libdriver_sqlite.so Aug 28 10:30:02 centosVM dovecot: auth: Debug: Module loaded: /usr/lib64/dovecot/auth/libmech_gssapi.so Aug 28 10:30:02 centosVM dovecot: auth: Debug: passwd-file /etc/dovecot/passwd.masterusers: Read 1 users Aug 28 10:30:02 centosVM dovecot: auth: Debug: auth client connected (pid=4693) Aug 28 10:30:27 centosVM dovecot: auth: Debug: client in: AUTH#0111#011PLAIN#011service=imap#011lip=10.0.2.15#011rip=10.0.2.2#011lport=143#011rport=59847#011resp=<hidden> Aug 28 10:30:27 centosVM dovecot: auth: Debug: auth(masteruser,10.0.2.2,master): Master user lookup for login: mailadm Aug 28 10:30:27 centosVM dovecot: auth: Debug: passwd-file(masteruser,10.0.2.2,master): lookup: user=masteruser file=/etc/dovecot/passwd.masterusers Aug 28 10:30:27 centosVM dovecot: auth: passwd-file(masteruser,10.0.2.2,master): unknown user Aug 28 10:30:29 centosVM dovecot: auth: Debug: client out: FAIL#0111#011user=masteruser What can be happening? Thanks, Clóvis -- Clovis Tristao - UNICAMP/Faculdade de Engenharia Agricola Administrador de Redes - Secao de Informatica (SINFO) E-mail: clovis(a)feagri.unicamp.br http://www.feagri.unicamp.br MSN: clovis_tristao33(a)hotmail.com Fone: 55(19) 35211031-35211038-35211047-91173116

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POP/IMAP HA solution for 5k users
by Sinergizmas Sin ergizmas 28 Aug '14

28 Aug '14

Hello, I want to build simple, cheap HA solution for 5000 users with postfix/dovecot. Each user will have 1.3 GB mailbox (maildir) storage quota. All of the users will use POP and also plus half of them will use IMAP from smart phones. Sometimes they will hit webmail (squirrelmail). I plan that every user will send 20 and receive 20 mails per day. I have 3 locations, but electricity are not very stable there. We have outages for couple of hours 3-4 times per year. So I plan distribute all servers (it's more like good PC's) across locations. I'm very tied on budget also. Or maybe I could say I don't have it and I'm forced to use hardware equipment which is given. We are talking about quite pour HA solution here. Don't judge me please. I start to plan architecture and I would be very thankful for all your thoughts. I'm not expert in this area, but I need to learn, fire up email system and manage it. I will have SMTP server (smtp.example.com) which will filter mail with Clam, Spamassasin, Greylisting and forward emails to IMAP/ POP3/webmail server (mail.example.com) Mail.example.com will sync all user and mail changes to the third server mail2.example.com. Mail2.example.com server is just stand by, hot backup server in cases if main mail server or smtp will not be reachable. Locations of servers are in different cities: Locations #1 - SMTP servers as virtual machines (vmware server or virtualbox), with CPU i3, 6GB RAM, SSD, Centos 6, Virtualmin Location #2 - Dovecot/webmail server: CPU i5, 16GB RAM, HDD 1SSD for OS/dovecot indexes and SATA 2TBx4 LVM (total 8TB) for Maildir's, Centos 6, Virtualmin Location #3 HOT BACKUP (always online) server in case of mail.example.com or smtp.example.com failure, electricity outage and etc. It contains Dovecot/webmail server: CPU i3, 8GB RAM, HDD 1SSD for OS/dovecot indexes and SATA 2x4TB LVM (total 8TB), Centos 6, Virtualmin DNS configuration (and location number): IN MX 10 smpt.example.com. (#1) IN MX 20 mail.example.com. (#2) IN MX 30 mail2.example.com. (#3) .... smtp IN A aa.aa.aa.aa mail IN A bb.bb.bb.bb mail2 IN A cc.cc.cc.cc So I need to solve SMTP, POP, IMAP high availability tasks. SMTP I think will be ok for external users. SMTP feature has all three servers. If smtp.example.com server is offline mail is sent to mail.example.com If mail.example.com is offline, then mail is sent to mail2.example.com If mail2.example.com is offline, the senders SMTP server will hold an email in a queue by default for 3 days (in most cases) and will try to deliver in some intervals. Local (users of domain example.com) SMTP/POP/IMAP users will have problems, because their domain server will be dead. This means that connections from user MTA agents (outlook POP) could not be delivered because DNS A type record pointing to a degraded server. When problem with server mail.example.com (POP/IMAP/webmail) connectivity will happen, I think to login to DNS server and point record (A type) to a working server. So if server in location #2 mail.example.com is dead, I will change mail IN A bb.bb.bb.bb ----> cc.cc.cc.cc The same with the server smtp.example.com. If it's down, I will change mail IN A aa.aa.aa.aa ----> cc.cc.cc.cc I know that this method is not perfect because of ISP DNS caching around the globe, but this the only option I have. Most of my users use ISP that refresh DNS in a period of 30 minutes so it won't be very terrible to half of hour to wait for the connection. My questions: 1. Is this infrastructure is ok for 5000 users? If you think it's not, please write how many users it will serve "normally"? Or maybe I it could handle and 10 000 users load? 2. Is the logic of all setup is right in such situation like mine? What other problems could arise? 3. I prefer to create users from one server. So the LDAP option is the best for me? In case of LDAP it will be on server #2 and I need to replicate it to #3. Is it rigth? Then server #2 will be offline does #3 LDAP will take place? Or should I better use batch command to create user in each server per single command? Actually I do not want to manage and LDAP as extra service. I don't have experience with it. 4. The main problem is to synchronize maildir of POP/IMAP/webmail servers. Because of distance I do not want to use DRBD. It's not suitable for WAN connections. GlusterFS seems an option but.. I saw on internet users also having problems with it performance. Sometimes gluster hang and all cluster must be restarted. Maybe I can sync /home with gluster where maildir resides, but we need to take care of dovecot index and control files synchronization also. The performance of retrieving index'es by several thousands users every 2-5 minutes must be excellent. The only option I found is Dovecot Dsync (or newer Doveadm) command. I made initial tests on two servers, but only to get work with SSH command. The method using TCP connection doesn't work for me. So question, if I use SSH method in several thousand user system does it cause me trouble? SSH adds some overhead comparing to TCP. But could make a permament tunnel and TCP also would be quite secure. So please tell me what methods are you using to sync two mail servers (especially for POP accounts) in different locations? 5. File system. Is it ok to use EXT4 file system? I know that XFS is better in performance working with small files (maildir = a lot of small files), but in power outage it can become corrupted without journal. Thanks.

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Fatal: master: service(imap): child 28145 killed with signal 11 (core dumped) -- started happening after upgrade last night
by Ben Johnson 28 Aug '14

28 Aug '14

Hello, I upgraded Dovecot last night and have been receiving core-dumps any time I attempt to access a mailbox (via IMAP) ever since. Logging-in seems to work, but any attempt to access the mailbox contents (regardless of folder) causes a core-dump. Please let me know if I can provide any additional details. apt Sources Details: # grep "dovecot" /etc/apt/sources.list deb http://xi.rename-it.nl/debian/ stable-auto/dovecot-2.2 main deb-src http://xi.rename-it.nl/debian/ stable-auto/dovecot-2.2 main Package Upgrade Details: Start-Date: 2014-08-14 19:30:57 Commandline: apt-get upgrade Upgrade: dovecot-sieve:amd64 (2.2.13-1~auto+138, 2.2.13-1~auto+150), dovecot-managesieved:amd64 (2.2.13-1~auto+138, 2.2.13-1~auto+150), dovecot-dev:amd64 (2.2.13-1~auto+138, 2.2.13-1~auto+150), dovecot-mysql:amd64 (2.2.13-1~auto+138, 2.2.13-1~auto+150), dovecot-core:amd64 (2.2.13-1~auto+138, 2.2.13-1~auto+150), dovecot-pop3d:amd64 (2.2.13-1~auto+138, 2.2.13-1~auto+150), dovecot-imapd:amd64 (2.2.13-1~auto+138, 2.2.13-1~auto+150) End-Date: 2014-08-14 19:32:39 Filesystem Details # df -T | grep "xvda1" Filesystem Type 1K-blocks Used Available Use% Mounted on /dev/xvda1 ext3 61796348 8037864 50612756 14% / ================= DOVECONF ================= # doveconf -n # 2.2.13 (c810e288aaed): /etc/dovecot/dovecot.conf # OS: Linux 3.13.0-24-generic x86_64 Ubuntu 14.04.1 LTS auth_mechanisms = plain login disable_plaintext_auth = no listen = *,[::] log_timestamp = "%Y-%m-%d %H:%M:%S " mail_debug = yes mail_max_userip_connections = 20 mail_privileged_group = vmail 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 duplicate passdb { args = /etc/dovecot/dovecot-sql.conf driver = sql } plugin { antispam_backend = mailtrain antispam_debug_target = syslog antispam_mail_notspam = --ham antispam_mail_sendmail = /bin/bash antispam_mail_sendmail_args = /usr/local/bin/sa-learn-pipe.sh antispam_mail_spam = --spam antispam_spam_pattern_ignorecase = SPAM;JUNK antispam_trash_pattern_ignorecase = trash;Deleted * antispam_verbose_debug = 1 quota = dict:user::file:/var/vmail/%d/%n/.quotausage quota_rule2 = Trash:storage=+100M quota_rule3 = Junk:ignore quota_rule4 = INBOX:storage=+100M quota_warning = storage=100%% quota-reached 100 %u %d quota_warning2 = storage=95%% quota-warning 95 %u %d quota_warning3 = storage=80%% quota-warning 80 %u %d quota_warning4 = -storage=100%% quota-below below %u %d sieve = /var/vmail/%d/%n/.sieve } postmaster_address = postmaster(a)example.com protocols = imap pop3 sieve service auth { unix_listener /var/spool/postfix/private/auth { group = postfix mode = 0660 user = postfix } unix_listener auth-userdb { group = vmail mode = 0600 user = vmail } user = root } service config { unix_listener config { group = vmail mode = 0600 user = vmail } } service imap-login { client_limit = 1000 process_limit = 500 } service quota-below { executable = script /usr/local/bin/quota-below.sh unix_listener quota-below { group = vmail mode = 0666 user = vmail } user = vmail } service quota-reached { executable = script /usr/local/bin/quota-reached.sh unix_listener quota-reached { group = vmail mode = 0666 user = vmail } user = vmail } service quota-warning { executable = script /usr/local/bin/quota-warning.sh unix_listener quota-warning { group = vmail mode = 0666 user = vmail } user = vmail } ssl_cert = </etc/postfix/smtpd.cert ssl_key = </etc/postfix/smtpd.key userdb { args = /etc/dovecot/dovecot-sql.conf driver = sql } protocol imap { mail_plugins = quota imap_quota antispam } protocol pop3 { mail_plugins = quota pop3_uidl_format = %08Xu%08Xv } protocol lda { mail_plugins = sieve quota } ================= CORE DUMP ================= # gdb /usr/lib/dovecot/imap /var/vmail/example.com/user/core Reading symbols from /usr/lib/dovecot/imap...(no debugging symbols found)...done. [New LWP 27866] [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". Core was generated by `dovecot/imap'. Program terminated with signal SIGSEGV, Segmentation fault. #0 0x00007f034d987a3e in array_idx_modifiable_i () from /usr/lib/dovecot/libdovecot.so.0 ================= SAMPLE MAIL LOG ENTRIES ================= Aug 15 19:39:30 xen dovecot: imap-login: Login: user=<ben(a)example.com>, method=PLAIN, rip=76.179.182.207, lip=192.64.115.178, mpid=29100, TLS, session=<Ki0NLrAAiwBMs7bP> Aug 15 19:39:30 xen dovecot: imap: Debug: Loading modules from directory: /usr/lib/dovecot/modules Aug 15 19:39:30 xen dovecot: imap: Debug: Module loaded: /usr/lib/dovecot/modules/lib10_quota_plugin.so Aug 15 19:39:30 xen dovecot: imap: Debug: Module loaded: /usr/lib/dovecot/modules/lib11_imap_quota_plugin.so Aug 15 19:39:30 xen dovecot: imap: Debug: Module loaded: /usr/lib/dovecot/modules/lib90_antispam_plugin.so Aug 15 19:39:30 xen dovecot: imap: Debug: Added userdb setting: mail=maildir:/var/vmail/example.com/ben/Maildir Aug 15 19:39:30 xen dovecot: imap: Debug: Added userdb setting: plugin/quota_rule=*:storage=0B Aug 15 19:39:30 xen dovecot: imap: Debug: Added userdb setting: plugin/sieve=/var/vmail/example.com/ben/.sieve Aug 15 19:39:30 xen dovecot: imap(ben(a)example.com): Debug: Effective uid=5000, gid=5000, home=/var/vmail/example.com/ben Aug 15 19:39:30 xen dovecot: imap(ben(a)example.com): Debug: Quota root: name=user backend=dict args=:file:/var/vmail/example.com/ben/.quotausage Aug 15 19:39:30 xen dovecot: imap(ben(a)example.com): Debug: Quota rule: root=user mailbox=* bytes=0 messages=0 Aug 15 19:39:30 xen dovecot: imap(ben(a)example.com): Debug: Quota rule: root=user mailbox=Trash bytes=+104857600 messages=0 Aug 15 19:39:30 xen dovecot: imap(ben(a)example.com): Debug: Quota rule: root=user mailbox=Junk ignored Aug 15 19:39:30 xen dovecot: imap(ben(a)example.com): Debug: Quota rule: root=user mailbox=INBOX bytes=+104857600 messages=0 Aug 15 19:39:30 xen dovecot: imap(ben(a)example.com): Debug: Quota warning: bytes=0 (100%) messages=0 reverse=no command=quota-reached 100 ben(a)example.com example.com Aug 15 19:39:30 xen dovecot: imap(ben(a)example.com): Debug: Quota warning: bytes=0 (95%) messages=0 reverse=no command=quota-warning 95 ben(a)example.com example.com Aug 15 19:39:30 xen dovecot: imap(ben(a)example.com): Debug: Quota warning: bytes=0 (80%) messages=0 reverse=no command=quota-warning 80 ben(a)example.com example.com Aug 15 19:39:30 xen dovecot: imap(ben(a)example.com): Debug: Quota warning: bytes=0 (100%) messages=0 reverse=yes command=quota-below below ben(a)example.com example.com Aug 15 19:39:30 xen dovecot: imap(ben(a)example.com): Debug: Quota grace: root=user bytes=0 (10%) Aug 15 19:39:30 xen dovecot: imap(ben(a)example.com): Debug: dict quota: user=ben(a)example.com, uri=file:/var/vmail/example.com/ben/.quotausage, noenforcing=0 Aug 15 19:39:30 xen dovecot: imap(ben(a)example.com): Debug: maildir++: root=/var/vmail/example.com/ben/Maildir, index=, indexpvt=, control=, inbox=/var/vmail/example.com/ben/Maildir, alt= Aug 15 19:39:30 xen dovecot: imap(ben(a)example.com): Fatal: master: service(imap): child 29100 killed with signal 11 (core dumped)

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Multiple ALT mail_location possible?
by Ralf Hildebrandt 28 Aug '14

28 Aug '14

http://wiki2.dovecot.org/MailboxFormat/dbox#Alternate_storage lists mail_location = mdbox:/var/vmail/%d/%n:ALT=/altstorage/vmail/%d/%n But can I have multiple ALT= locations? Background: I want to migrate to a hashing-scheme! -- [*] sys4 AG http://sys4.de, +49 (89) 30 90 46 64 Franziskanerstraße 15, 81669 München Sitz der Gesellschaft: München, Amtsgericht München: HRB 199263 Vorstand: Patrick Ben Koetter, Marc Schiffbauer Aufsichtsratsvorsitzender: Florian Kirstein

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Moving from one Dovecot server to another Dovecot server
by Michael 28 Aug '14

28 Aug '14

Hi, I'm planning to move all mailboxes from a Dovecot 2.2.10 server to a Dovecot 2.2.9 server. Dovecot is serving virtual users only. I'm not sure if I can use dsync for that. According to the Wiki [1] the command to mirror my own mailbox should look like dsync -u mine(a)michi.su mirror ssh -i my_ssh_key vmail(a)my-mailserver.com dsync -u mine(a)michi.su Where vmail is the user that is used by Dovecot to access mail_location. I assume the above command will only mirror the mailbox of user mine(a)michi.su, right? Is it possible to sync all mailboxes with just one single command? Is it possible to sync also all ACL lists and sieve scripts? Is using dsync the right way for my purpose? Thanks, Michael [1] http://wiki2.dovecot.org/Tools/Dsync

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