- dovecot - dovecot.org

[Dovecot] Installation of Dovecot
by Steven F Siirila 02 Nov '06

02 Nov '06

When I configure Dovecot to conform to our directory hierarchy, it insists on adding 'dovecot/' to the prefixes I specify. Is there any way to inhibit this? My configure command is: ./configure --prefix=/opt/dovecot --sysconfdir=/etc/opt/dovecot \ --libexecdir=/opt/dovecot/libexec --localstatedir=/var/opt/dovecot \ --without-sql-drivers --with-ssl=openssl \ --with-ssldir=/etc/opt/dovecot My problem is with the resulting directories: /opt/dovecot/libexec/dovecot is used instead of /opt/dovecot/libexec /var/opt/dovecot/lib/dovecot is used instead of /var/opt/dovecot/lib /var/opt/dovecot/run/dovecot is used instead of /var/opt/dovecot/run It seems that Dovecot assumes that libexecdir and localstatedir refer to non-Dovecot-specific directories, and adds 'dovecot/' to the path. Is there any way to avoid this? In our environment )we use: /opt/XXX Optional software XXX /etc/opt/XXX Configuration for optional software XXX /var/opt/XXX Variable data for optional software XXX (Which makes for easier upgrades) -- Steven F. Siirila Office: Lind Hall, Room 130B Internet Services E-mail: sfs(a)umn.edu Office of Information Technology Voice: (612) 626-0244 University of Minnesota Fax: (612) 626-7593

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[Dovecot] Maildir++?
by Marten Lehmann 02 Nov '06

02 Nov '06

Hello just to have up2date records: Is the current dovecot release capable of the maildirsizefile as described in http://www.exim.org/exim-html-4.63/doc/html/spec_html/ch26.html#id2643923 ? Regards Marten

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[Dovecot] Fw: POP 23 problem
by Manoj Fernandez 02 Nov '06

02 Nov '06

Hi there I am using Dovecot on Ubuntu 6 LTS forPOP3 services. The user account created at installation works fine and Iam able to log to POP3 services by telnetr. When I created a another user and tried tologin via telnet this is what happens telnet XXX.XXX.XXX.XXX 10 + OK Dovecot ready user XXXX + OK pass XXX +OK logged in Connection tohost lost and session terminates. Pls advise what could be the problem Tks Manoj Sri Lanka

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[Dovecot] imap process crashing with "file mail-cache-fields.c: line 26: unreached"
by JB Zimmerman 02 Nov '06

02 Nov '06

Hoping someone's seen this and/or can help...heh. I'm running the at rpm of dovecot, version dovecot-1.0-0_27.rc10.el4.at. I'm running it on RHEL4, up to date. We're using Maildir (we're upgraded from a Courier-IMAP installation) and things are working...but...we have a few users with very large mailboxes (not their inboxes) where they archive stuff (200k+ messages). When they try to read those mailboxes, the imap server instantly drops the connection, and I get the following in the log: --cut-- Oct 27 11:20:11 hostname dovecot: IMAP(user): file mail-cache-fields.c: line 26: unreached Oct 27 11:20:11 hostname dovecot: child 27514 (imap) killed with signal 6 --cut-- host and user names changed to protect the guilty. I have tried increasing the imap process size max to 512, as well as doubling the IMAP command size to 131072 (bytes)? Neither made a difference. *other* mailboxes on the same account work fine. The error happens *immediately*, not after a timeout, as soon as they select the mailbox in their client (we're using Evolution, and have tried pine as well...I'm working on trying other clients). The Maildir caching optimization settings in the conf are left to default. Any ideas? Many thanks. J.B. Zimmerman --

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Re: [Dovecot] Clustering (replication and proxying) plans for the future
by Bill Boebel 02 Nov '06

02 Nov '06

On Tue, October 24, 2006 2:31 pm, Timo Sirainen <tss(a)iki.fi> said: > The replication could work simply by sending the transaction logs' > contents to the replicatio process which passes it onto other servers, > which finally sync their local mailboxes based on that data. Since > Dovecot already is able to sync mailboxes based on the transaction log's > contents this should be pretty easy to implement. > > Of course the new mails' contents also have to be sent. This could be > prioritized lower than the transaction traffic, so that each server > always has very up-to-date view of the mailbox metadata, but not > necessarily the contents of all the mails. > > If the server finds itself in a situation that it doesn't have some > specific mail, it'll send a request to the replication process to fetch > it ASAP from another server. The reply will then take the highest > priority in the queue. Is your primary goal with this replication to add redundancy or to distribute load such as for shared mailboxes? I've thought about the redundancy side of this a lot, but not so much about load distribution. It sounds like you're going for load distribution, but... If the goal is redundancy, I'd suggest that mailbox state is less important than the mail data. Index files can be recreated from the data, and would not even be needed on the secondary server(s) unless the primary fails. So I'd put a higher priority on getting the mail content to the secondary servers. If the goal is to distribute load for shared mailboxes, then your prioritization makes sense. Also, if the goal is redundancy, this design can be simplified a lot by having one master and one or more slaves. All modify operations would go to the master, so that you do not need global locks. Different sets of users would belong to different namespaces, so that you can have multiple replication paths in your cluster. You'd also want an API for the replication process so that third-party applications that modify mailboxes can log those changes so that they are replicated. And in that case, the replication process could be made generic enough so that it can be used to replicate any set of files, with or without Dovecot. Bill

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[Dovecot] http://dovecot.org/tools/
by Gavin Henry 01 Nov '06

01 Nov '06

Dear all, Could this be added to http://dovecot.org/tools/ http://cpan.org/authors/id/G/GH/GHENRY/create_dovecot_shares-1.05 Thanks. -- Kind Regards, Gavin Henry. Managing Director. T +44 (0) 1224 279484 M +44 (0) 7930 323266 F +44 (0) 1224 824887 E ghenry(a)suretecsystems.com Open Source. Open Solutions(tm). http://www.suretecsystems.com/

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[Dovecot] CRASH: mail-cache-fields.c crash - new info, hacked 'solution'
by JB Zimmerman 01 Nov '06

01 Nov '06

I'm baaaaack. :-) I've managed to implement a suggestion from Hans Morten Kind from this list that seems to have stopped the crashing. However, my hack - commenting out a call to i_unreached() - makes me queasy because I have no idea of the ramifications of it (I don't habitually code, myself). So I wanted to lay it out for y'all in case this is a problem that you feel should be looked at. So, here's my situation. Using dovecot-1.0.rc10 downloaded from dovecot.org. Built an RPM locally on my machine (as opposed to prior attempts, which used the AT rpms), which is running RHEL 4AS with all updates. Did *not* configure in postgres, mysql, sqlite, ldap-auth. Other than that, stock (openssl included, eg) - some file locations taken from AT RPMs' spec (redhat specific file locs). No patches performed. SPEC available if y'all think it'd help; the RPM built with no complaints, installed same. Using Maildir format, upgraded from a Courier install, so .folder.subfolder structure. Error behavior: When a user attempted to open a folder containing large numbers of messages (roughly 100k+ messages, as far as we can tell) they immediately got an error saying the server has disconnected. On the server side, I got this in the log (hostname 'magneto' obviously) ---cut--- Nov 1 15:18:16 magneto dovecot: IMAP(joeuser): file mail-cache-fields.c: line 26: unreached Nov 1 15:18:16 magneto dovecot: child 17599 (imap) killed with signal 6 ---cut--- Now, the folder in question is a folder of CVS commit messages (hence the size). If I go into the folder ("/home/joeuser/Maildir/.GNOME CVS commits/") and do 'rm -f dovecot-*' and then have the user try again, then they can open the folder and get a message list. dovecot will rebuild the various index files. However, as soon as they click on an individual message, bam, the same error behavior - and from then on, they can't get into the folder again unless we remove their dovecot files again. We tried this using Evolution, mutt and pine as the clients. All exhibited identical behavior. This is coming over TLS. NOW THE FIX: I made a change to the source (gasp!) that honestly I have no idea the ramifications of, but it has...well, not *fixed*, but sorta fixed it. As per Hans Morten Kind, I commented out the i_unreached() call in field_has_fixed_size(). After this, the mail is readable as is the folder list, but now there is an error message in the log. First things first, here's the change I made to dovecot-1.0.rc10/src/lib-index/mail-cache-fields.c: ---cut--- @@ -23,7 +23,7 @@ return FALSE; } - i_unreached(); +/* i_unreached(); */ return FALSE; } ---cut--- ...and here's what now happens in the log, to the same mail folder as above: ---cut--- Nov 1 15:59:42 magneto dovecot: IMAP(joeuser): Corrupted index cache file /home/joeuser/Maildir/.GNOME CVS commits/dovecot.index.cache: field header names corrupted ---cut--- At that point, I deleted the cache files again, and the error goes away. I also notice that the index.cache file in that folder is much, much larger than it was, from which I posit that the above error was because the crashing imap process had left an incomplete index file. Removing it thus forced a rebuild with the new code which seems to have fixed the problem. Thank you all for your patience. I hand this willingly over to the list. jb -- ------------------------------------ J.B. Zimmerman jbz(a)ximian.com Network Administrator Ximian - http://www.ximian.com ...a tiny little division of Novell.

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[Dovecot] Real and Virtual Users + Domains
by Gerard Seibert 01 Nov '06

01 Nov '06

I have seen a few suggestions on how to address the issue of a system employing both real and virtual users and domains. Is there any definitive solution as to how this should be accomplished? The system I am construction will have several hundred users, both real and virtual, and probably seven domains. I plan on using MySQL to handle the user names and passwords. -- Gerard "Seen it all, done it all, can't remember most of it." Anonymous

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[Dovecot] Upgrade from RC7 to RC10 didn't go too well...
by Dominic Lepiane 01 Nov '06

01 Nov '06

Hi, On the weekend I tried to upgrade from RC7 to RC10. Clearly, I have to change some things before I can do this. What does it take to get to RC10? As is, my mail client got an error trying to list messages in /INBOX (via IMAP) and the mail.err log shows the following messages: Oct 29 10:27:32 siona dovecot: IMAP(archangel): open(/var/mail/archangel/inbox, O_CREAT) failed: Not a directory Oct 29 10:27:32 siona dovecot: IMAP(archangel): mkdir_parents(/var/mail/archangel/.imap/INBOX) failed: Not a directory Oct 29 10:27:32 siona dovecot: IMAP(archangel): open() failed with subscription file /var/mail/archangel/.subscriptions: Not a directory My dovecot.conf includes default_mail_env = mbox:/var/mail/%u And other then enabling SSL, I've got a pretty vanilla configuration (e.g. nothing in the IMAP section at all, no odd namespaces...) /var/mail/archangel is an mbox file, why is dovecot trying to open files under there? I know at least part of the discussion has happened on the list before so I'm sorry for duplicating other questions. My TODO is about ten km long so I hope someone can at least give me a couple good pointers. Thanks in advance! -- Dominic Lepiane The IRMACS Centre

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[Dovecot] Dovecot delivery
by Hr. Daniel Mikkelsen 01 Nov '06

01 Nov '06

Hi. Does the dovecot deliver helper program now support maildirs? Are there plans to support this? -- Daniel Mikkelsen Copyleft Software AS

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Re: [Dovecot] Redundant shared mail store?
by Joshua Goodall 01 Nov '06

01 Nov '06

dovecot(a)redigloo.org wrote: > My ears prick up whenever I hear mention of NetApps and Dovecot. > > Which operating system (Linux, Solaris, Solaris x86...) are you > running. The NFS clients w/Dovecot are currently running Linux 2.6.16 with Trond Myklebust's Linux-2.6.16-NFS_ALL.dif applied (see http://client.linux-nfs.org/) This combo has been stable for months. And yes, we use fcntl locking, and mount noac,actimeo=0. JG

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[Dovecot] moving public folders to private Trash
by Mark Nienberg 01 Nov '06

01 Nov '06

Using Thunderbird 1.5.0.4 against dovecot beta9: If a user has Thunderbird configured to move deleted messages into a Trash folder, then the user cannot delete folders in a public namespace. There is no problem deleting messages. Thunderbird says: "The current command did not succeed. The mail server responded: Can't rename mailbox to another storage type." All mailboxes (public and private) are maildir format. Users can successfully delete folders from their own private areas, and the folders then appear as subfolders of the Trash folder. Also, users can reconfigure Thunderbird to delete messages immediately instead of moving them to trash and then successfully remove public folders. Also, users can move public folders within the public namespace. So I think the problem boils down to the inability to move a folder from a public namespace to a private one, which is what happens when Thunderbird is configured to move deleted messages to a Trash folder. Mark Nienberg

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[Dovecot] IMAP Dovecot with ISPConfig and shared folders?
by Perry 31 Oct '06

31 Oct '06

Fedora 5, postfix, dovecot, ISPConfig server all running well, (don't want to break it) LOL. But, I do not have IMAP shared folders. These instructions on dovecot tell of how to setup namespace to be able to get shared folders. http://wiki.dovecot.org/SharedFolders But given everything is relative in ISPConfig, not sure if this is possible or if I could really mess things up. What tells dovecot to look in the various different web# folders for email? Am I better off using Symlinking??? Thanks much for all comments and direction. ____________________________________________________________________________________ Cheap Talk? Check out Yahoo! Messenger's low PC-to-Phone call rates (http://voice.yahoo.com)

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Re: [Dovecot] Redundant shared mail store?
by Joshua Goodall 31 Oct '06

31 Oct '06

Jasper Bryant-Greene wrote: > Hi guys > > I'm about to embark on a project replacing a legacy single mail server > running proprietary software with a cluster of Dovecot servers. We > clearly need a shared mail store for these servers, but we are not happy > with simply using a server running NFS as this becomes a single point of > failure. > > What have other people used? AFAICT our options are: > > * A shared block device (Fibre Channel, iSCSI, ATAoE etc) running > GFS > or similar to allow multiple servers to access it concurrently > > * Two or more NFS units, either with built-in support for > replication > of FS changes and failover, or with scripts for achieving this > functionality > > I prefer option 1, although it's expensive. What have other people used? > Do we have other options? I recommend a pair of NetApp filers (e.g. 2 x 3020c) exporting NFS from shared disk shelves in their high-availability mode. This is a hybrid of the two options, except a) it's a fully supported and stable NetApp configuration, b) they're sharing disk storage, c) you're not hog-tied to GFS, d) it's the best NFS implementation in the world (you can even trust the fcntl locking), e) it's really fast, f) NetApp's onboard snapshots and other funky software bits will make you wonder how you lived without them, g) the HA actually works. I have a six-digit userbase with mailboxes in this configuration. JG

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[Dovecot] auth both system and virtual users
by Gerry Reno 31 Oct '06

31 Oct '06

I've setup dovecot to auth both system and virtual users but it is refusing to work. It keeps saying user is not found. Is there something more that I need to set? dovecot.conf: ============================================================================ = default_mail_env = maildir:/var/mail/%1.1u/%u/Maildir mail_extra_groups = mail protocol imap { } protocol pop3 { } protocol lda { postmaster_address = postmaster(a)example.com } auth_verbose = yes auth_debug = yes auth_debug_passwords = yes auth default { mechanisms = plain passdb passwd-file { args = /etc/dovecot.deny deny = yes } passdb passwd-file { args = /etc/imap.passwd } passdb pam { } userdb passwd { } user = root } dict { } plugin { } ============================================================================ = maillog: ============================================================================ = Oct 30 20:12:00 grp-01-10-01 dovecot: Killed with signal 15 Oct 30 20:12:03 grp-01-10-01 dovecot: Dovecot v1.0.rc7 starting up Oct 30 20:12:04 grp-01-10-01 dovecot: auth(default): passwd-file /etc/dovecot.de ny: Read 0 users Oct 30 20:12:04 grp-01-10-01 dovecot: auth(default): passwd-file /etc/imap.passw d: Read 1 users Oct 30 20:12:24 grp-01-10-01 dovecot: auth(default): client in: AUTH 1 PLAIN service=IMAP secured lip=::ffff:127.0.0.1 rip=::ffff:127.0.0.1 resp=AHR1c2VyAHBhc3M= Oct 30 20:12:24 grp-01-10-01 dovecot: auth(default): passwd-file(tuser,::ffff:12 7.0.0.1): unknown user Oct 30 20:12:24 grp-01-10-01 dovecot: auth(default): client out: OK 1 user=tuser Oct 30 20:12:24 grp-01-10-01 dovecot: auth(default): master in: REQUEST 1 30764 1 Oct 30 20:12:24 grp-01-10-01 dovecot: auth(default): passwd(tuser,::ffff:127.0.0 .1): unknown user Oct 30 20:12:24 grp-01-10-01 dovecot: auth(default): userdb(tuser,::ffff:127.0.0 .1): user not found from userdb Oct 30 20:12:24 grp-01-10-01 dovecot: auth(default): master out: NOTFOUND 1 Oct 30 20:12:24 grp-01-10-01 dovecot: imap-login: Internal login failure: user=< tuser>, method=PLAIN, rip=::ffff:127.0.0.1, lip=::ffff:127.0.0.1, secured ~ ============================================================================ =

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[Dovecot] Problem report
by leslie.polzer＠gmx.net 31 Oct '06

31 Oct '06

Hello guys, Dovecot is a great IMAP server, I really like it :) I recently found an annoying problem, however: To sync my mail, I use OfflineIMAP, which usually works very smoothly. A spam mail with the year set to 2038 produced the error message "Invalid internal date" when OfflineIMAP tried to upload it to the server. Only deleting the messag helped. The usual data: Dovecot 0.99.14-1sarge0 on Debian Sarge x86. It would be nice to remove this date-smartness (?)... Kind regards, Leslie -- gpg --keyserver pgp.mit.edu --recv-keys DD4EBF83 http://nic-nac-project.de/~skypher/

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[Dovecot] Continuing problems with zombied dovecot-auth procs; mail-cache-fields.c IMAP procs crashing
by JB Zimmerman 31 Oct '06

31 Oct '06

Folks- Hans Morten Kind was kind enough to confirm the issue I'm having with large mailboxes and the mail-cache-fields.c file (line 26: unreached error in logs when the imap process crashes out on large Maildirs). Has anyone implemented a fix for this that is both tested and applicable without making manual code changes myself, since I don't trust myself slashing about in source files? Ideally, has this problem been noted for fixing in a newer version? Failing that, if I downgrade to the 0.99 version shipped with RHEL4, has anyone found that to be more reliable? I used the 1.0rc10 in order to gain access to the 'namespace' conf directives so that upgrading from our current Courier Maildir installations would be as seamless as possible, but at the moment, I'm looking at having to roll back to Courier in order to fix this (and the next) problem. Also, we have found that using 1.0rc10 on RHEL4, using pam-ldap for account info and pam-krb for auth, has resulted in the eventual inaccessability of mail due to many zombied and unresponsive dovecot-auth processes. Restarting dovecot the first few times it becomes unresponsive will fix the problem, presumably by instantiating new auth procs, but eventually this no longer works since the restart doesn't actually kill off the zombied auth procs and the socket stops responding. Has anyone run into this problem? Thanks, J.B. Zimmerman RHEL4AS, fully updated, using the AT rpms: dovecot-1.0-0_27.rc10.el4.at --

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[Dovecot] [Patch] vpopmail plaintext passwords
by Remi Gacogne 31 Oct '06

31 Oct '06

Hello, This patch enables APOP and CRAM-MD5 when using vpopmail auth. Remi Gacogne Aqua Ray SARL

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[Dovecot] Multiple certificates
by Phill Edwards 31 Oct '06

31 Oct '06

I have dovecot version 1.0 relese 0.beta8.2.fc5 installed on my FC5 linux box. It acts as an IMAP server to my home LAN. I connect to it from the home PCs over SSL and have installed a certificate in the domain imap.edwards.home to enable this. However, I also use a web site called www.xs2mail.com which retrieves the email from my IMAP server (which has a public DNS entry called XXX.homelinux.com) and displays them in a web interface. I used to run uw-imap and this all worked fine. But since I went to Dovecot I can't use that site any more because it gives me this message: Login failure: Certificate failure for XXX.homelinux.com: self signed certificate: /C=AU/ST=NSW/L=Sydney/O=Edwards/OU=IMAP server/CN=imap.edwards.home/emailAddress=philledwards(a)gmail.com I assume it's getting upset because the certificate is for imap.edwards.home but the domain it's connecting to is XXX.homelinux.com. Is there a way to resolve this? I read something about using virtual servers but all I could find is this in a post somewhere - I don't know which file it goes, where in that file etc: <snip> 1.0-tests support "virtual servers", where this is possible: server foo { listen = 1.2.3.4 ssl_cert_file = /etc/ssl/certs/foo.cer } server bar { listen = 1.2.3.5 ssl_cert_file = /etc/ssl/certs/bar.cer } </snip> Can anyone help me figure this out? (PS - I can't just set up my own IMAP web interface because I can't run anything on port 80 with my ISP and I can't get out of our company firewall on anything other than port 80). Thanks in advance, Phill

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[Dovecot] www.dovecot.org misconfigured?
by Steven F Siirila 30 Oct '06

30 Oct '06

I am having difficulting getting to www.dovecot.org and wiki.dovecot.org. My browser tells me it can't find them. Anyone know what's up? -- Steven F. Siirila Office: Lind Hall, Room 130B Internet Services E-mail: sfs(a)umn.edu Office of Information Technology Voice: (612) 626-0244 University of Minnesota Fax: (612) 626-7593

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[Dovecot] dovecot auth + postifx: how to disable PLAIN and LOGIN without TLS?
by Lev Serebryakov 29 Oct '06

29 Oct '06

Hello dovecot, I want to have all authorization in one place and don't use Cyrus-SASL. I cobfigure postfix 2.3.3 to use dovecot-SASL. I have next lines in main.cf: smtpd_sasl_security_options = noplaintext,noanonymous smtpd_sasl_tls_security_options = noanonymous But PLAIN and LOGIN are advertised by postfix :( Is it bug of postfix or dovecot-auth? I don't want to disable these mechanisms in auth {} stanza of dovecot.conf, because they are Ok over SSL/TLS. It works for dovecot-pop3 and dovecot-imap, but not for postfix :( postfix 2.3.3, dovecot 1.0rc10. -- Best regards, Lev mailto:lev@serebryakov.spb.ru

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[Dovecot] LSUB and namespaces - how to get rid of multible prefixes
by Henrik Ostergaard Madsen 28 Oct '06

28 Oct '06

I'm using dovecot 1.0.rc7 and Squirrelmain 1.4.8 using IMAP on a Debian 3.1 Testing system, and I'm having a problem. When Squirrelmail (or other IMAP clients) submits an LSUB "" "*%", dovecot responds with: Request: A004 LSUB "" "*%" Response: * LSUB () "/" "INBOX.Sent" * LSUB () "/" "INBOX.Trash" * LSUB () "/" "INBOX.Drafts" * LSUB () "/" "mail/Sent" * LSUB () "/" "mail/Trash" * LSUB () "/" "mail/Drafts" * LSUB () "/" ".mail/Sent" * LSUB () "/" ".mail/Trash" * LSUB () "/" ".mail/Drafts" * LSUB () "/" "Sent" * LSUB () "/" "Trash" * LSUB () "/" "Drafts" * LSUB () "/" "INBOXSent" * LSUB () "/" "INBOXTrash" * LSUB () "/" "INBOXDrafts" * LSUB () "/" "./INBOX.Sent" * LSUB () "/" "./INBOX.Trash" * LSUB () "/" "./INBOX.Drafts" * LSUB () "/" "Test" Lsub completed. This is in spite of that only INBOX.Sent, INBOX.Trash, INBOX.Drafts and Test actually exists. I have tried with no explicit namespaces, only one with no prefix or with prefix "/", and with that again and all the above prefixes marked as hidden, but with absolutely no change in the LSUB repons. Due to this, Squirrelmail shows up a whole bunch of folders, but only the correct ones (without prefixes) works.. This has been the same with a few prior versions of dovecot 1.0 , but not with dovecot 0.99. It is the same for Squirrelmail 1.4.7, but I do not think the client matters.. Is there a setting or way to deal with this - or is it a bug? Regards, Henrik

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[Dovecot] "dovecot dead but subsys locked" problem
by Carla Tironi Farinati 27 Oct '06

27 Oct '06

Hi, Following the advice of someone really helpfull here, I just installed Postfix/Dovecot (from rpms). I'm running CentOs 4.4. I followed this guide: http://www.howtoforge.com/linux_postfix_virtual_hosting I've got two problems, a)my server is now listed as RCB, whatever that means, I suppose that's close to spamming. "0: Connection refused. Your IP address is blocked(Spamhaus XBL) - see http://www.spamhaus.org/query/bl?ip=216.32.68.90 " b)[root@server ssl]# /etc/init.d/dovecot restart Stopping Dovecot Imap: [FAILED] Starting Dovecot Imap: [ OK ] [root@server ssl]# /etc/init.d/dovecot status dovecot dead but subsys locked I deleted the sybsys file and tried to restart it. It crashes and show the error agsin. The logs don't show up anything unusual. I also see in the logs: Oct 25 22:50:07 server postfix/virtual[24712]: 48BA5904990: to=<carlatf(a)ithaki.net>, relay=virtual, delay=1, status=deferred (mailbox /var/spool/vmail/ithaki.net/carlatf: cannot open file: Is a directory) Of course it's a directory!. I created it following the guide! I reinstalled Dovecot with the latest sources and nothing. I also turn off SSL from dovecot's config file, nothing. Any ideas dovecot gurus!? Best regards, Carla

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[Dovecot] Clustering (replication and proxying) plans for the future
by Timo Sirainen 27 Oct '06

27 Oct '06

I wrote this mostly so that I won't forget my thoughts. Most likely won't be implemented anytime soon. I haven't thought through all the locking issues. It would require a distributed lock manager in any case. I think there are already several existing ones, so one of them could probably be used for Dovecot. Each mail server would consult a master server for getting namespace configuration and location for shared/public mailboxes. If the data is stored in some central SQL server there could just as well be multiple master servers (or even each server be their own master). Whenever trying to open a shared mailbox that doesn't exist in the current server, the imap process would automatically create a new connection for the destination server and start proxying the data. The proxy would be a somewhat dummy proxy, which just forwards the client's commands to it and doesn't even try to understand the replies from the remote server. So admin will have to be careful to use only servers which have all the capabilities that were announced by the original server. So, then the replication. Each namespace could be configured to be available either by proxying or by replication: namespace public { prefix = example/ location = proxy:imap.example.com } namespace public { prefix = example/ replicated_to = host1.example.com host2.example.com # If multi-master, we'll need to use global locking. If not, the # replicated_to servers contain only slaves. multi_master = yes location = maildir:~/Maildir } The way this would work is that each imap process connects via UNIX socket to a replication process, which gets input from all the imap processes. The replication process keeps track of how much has been sent to each other server and also the acks it has received from them. So if the network dies temporarily it'll start writing the changes to the disk until it reaches some limit, after which a complete resync will be necessary. Dovecot already writes all the changes to a mailbox first to a transaction log file and and only afterwards it updates the actual mailbox. The contents of the new mails aren't stored there though. The replication could work simply by sending the transaction logs' contents to the replicatio process which passes it onto other servers, which finally sync their local mailboxes based on that data. Since Dovecot already is able to sync mailboxes based on the transaction log's contents this should be pretty easy to implement. Of course the new mails' contents also have to be sent. This could be prioritized lower than the transaction traffic, so that each server always has very up-to-date view of the mailbox metadata, but not necessarily the contents of all the mails. If the server finds itself in a situation that it doesn't have some specific mail, it'll send a request to the replication process to fetch it ASAP from another server. The reply will then take the highest priority in the queue. Normally when opening or reading the mailbox there's really no need to do any global locking. The server will show the mailbox's state to be what it has last received from the replication process. Whenever modifying the mailbox a global lock is required. Here's also the problem that if the network is down between two servers, they both think that they got the global lock. If they did any conflicting changes, they'll have to be resolved when both of them again see each others. Dovecot's transactions in general aren't order-dependent so most of the conflicts can be resolved by just having the replication master decide which way the transactions were done and then sending the transactions back to all of the servers in that order. Adding new messages is a problem however. UIDs must be always growing and they must be unique. I think Cyrus solved this by having 64bit global UIDs which really uniquely identify the messages (ie. first 32bits contain server-specific UID), and then the 32bit IMAP UIDs. If there are any conflicts with the IMAP UIDs, they're given new UIDs (which invalidates clients' cache for those messages, but that can't be helped). Resyncing works basically by requesting a list of all the mailboxes, opening each one of them and requesting new transactions from the log files with <UID validity>, <log file sequence>, <log file offset> triplet. If UID validity has changed or log file no longer exists, a full resync needs to be done. Also if the log file contains a lot of changes, it's probably faster to do a full resync. Full resync would then be just sending the whole dovecot.index file. Conflict resolving could also require a full resync if transaction logs were lost. That'd work again by the master receiving everyone's dovecot.index files, deciding what to do with them and sending the modified version back to everyone. Each server has different transaction logs, so the log file sequences can't be directly used between servers. So the replication process probably will have to keep track of every server's log seq/offset. Also when receiving full dovecot.index files they'll have to be updated in some way. Then there's the problem of how to implement the receiving side. If the user already has a process connected to the replication process it could be instructed to update the mailboxes. But since this doesn't happen all that often, there also needs to be some replication-writer process which writes all the received transactions to the mailboxes. Now, when exactly should these replication-writer processes be created then? If all users have the same UNIX user ID, then there could be a spool of processes always running and doing the writing. Although this worries me a bit since the same process is handling different users' data. More secure way, and the only way if users have different UNIX UIDs, is to launch a separate writer process for each user. It probably isn't a great idea to do that immediately when receiving data for a user, but to queue data for the user for a while and then once enough has been received or some timeout has occurred, the writer process would be executed. There probably should be some shared in-memory cache with a memory limit of some megabytes, after which data is written to disk up to a configurable amount. Only after that is full or timeout for the user is reached, the writer process is executed and the data is sent to it. All this replication stuff could also be used to implement a remote mail storage (ie. smarter proxying). The received indexes/transactions could simply be kept in memory, and all the mails that aren't already cached in memory could just be requested from the master whenever needed. I'm not sure if there's much point in doing this over dummy proxying though.

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[Dovecot] dovecot.org not resolving!
by /dev/rob0 27 Oct '06

27 Oct '06

I had to bypass my unknown sender/recipient domain restrictions to receive list mail and send this. It's hard to say without a whois server for .fi, but it appears that the problem might be with the procontrol.fi. domain. Action to fix the problem is needed ASAP! I've emailed Timo offlist; also tried to get him in IRC. -- Offlist mail to this address is discarded unless "/dev/rob0" or "not-spam" is in Subject: header

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