- dovecot - dovecot.org

[Dovecot] Dovecot behaviour when the server's file system fails (possible feature request)
by Timo Neuvonen 08 Oct '06

08 Oct '06

I've met a couple of times a situation, that there is something wrong with the mail server's operating system / file system, but Dovecot is still working, although it cannot any more access the mailbox files. The result is, that the imap mail client in the workstation automatically synchronises with the improperly empty-looking mailbox, effectively deleting everything previously loaded into the workstation's mail client (eg. Outlook Express) when using imap protocol. This is very annoying, especially when the workstation isn't connected with a high-speed-enough connection, since after the server is properly brought up again, reloading all the contents of the improperly emptied mail client may take considerable amount of time. This is especially the case, if the workstation has kind of mobile connection (eg. gprs) with very limited bandwith -in that case the sychronizing of eg. 20MB account may take at least from half an hour to more than one hour, and in some cases (eg. gprs roaming) also cost considerable amount of money (gprs data transfer may cost from eg. 5 to over 10 euros or dollars per megabyte, when roaming outside the phone operator's own network). So, is there currently a way to configure Dovecot in a way it would recognize that the mailbox actually is not accessible, and in that case it would return an error message to the mail client instead of returning "empty mailbox"? Of course, a smart enough mail client might also ask something from the user, but that seems not be the case either... If this behavious cannot be changed with the current configuration options, then a kind feature request to the developer: Would it be possible to change the behaviour of Dovecot when it actually can not access the mailbox files? Although the actual problem in this case is outside Dovecot, this kind of improvement would greatly improve the error tolerance of the whole system. -- TiN

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[Dovecot] fd leak in 1.0rc7?
by Quentin Garnier 08 Oct '06

08 Oct '06

Hi, I just upgraded a 0.99 installation to 1.0rc7 (going from mbox to maildir along the way, but that's another story), and I'm seeing a rather fast fd quick; I already had to restart dovecot once, after a few hours. What is leaked are pipes, left open on the master dovecot process while the other end is long gone. I can't tell right now if it happens for every single login process spawned (either pop3 or imap), but at least a lot of them. FWIW, I'm running dovecot 1.0rc7 on NetBSD 2.0.3_STABLE. I'll try debugging tomorrow, but if anyone has an idea what happens in the meantime, I'm all hears. -- Quentin Garnier - cube(a)cubidou.net - cube(a)NetBSD.org "When I find the controls, I'll go where I like, I'll know where I want to be, but maybe for now I'll stay right here on a silent sea." KT Tunstall, Silent Sea, Eye to the Telescope, 2004.

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[Dovecot] Pop3s duplicates
by Mark Adams 08 Oct '06

08 Oct '06

Hi, dovecot 1.0 rc6 Can someone please advise on my interpretation of the following logs, Users are reporting duplicate email coming through to their inbox. (user@domain replaced actual username and domain) There are also reports of the connection seemingly freezing whilst the emails are being downloaded (pausing at a certain amount of kB then continuing after a minute or 2). info: pop3-login: Login: user=<user@domain>, method=PLAIN, rip=89.192.*.**, lip=172.16.22.10, TLS info: POP3(user@domain): Disconnected top=0/0, retr=4/183443, del=0/313, size=83779942 info: pop3-login: Login: user=<user@domain>, method=PLAIN, rip=89.192.*.**, lip=172.16.22.10, TLS info: POP3(user@domain): Disconnected top=0/0, retr=3/183443, del=0/322, size=84201570 In the first instance the user downloaded 4 emails totalling 183443 bytes leaving 313 messages on the server. (outlook 2003 set to leave a copy of messages on the server) second instance user downloaded 3 emails, exactly the same amount of bytes and left 322 messages on the server. Does this mean the users connection was interrupted when downloading the original emails and they attempted to be sent again a second time? how could it be that there are 9 emails left on the server if only 3 extra were downloaded? Any help on this would be much appreciated. Thanks, Mark

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[Dovecot] coding techniques
by David Lee 08 Oct '06

08 Oct '06

Whilst debugging a problem in dovecot LDA over the last few days, I came across two different issues in coding techniques. (Note: Please don't take this negatively; my intent is both positive and constructive!) The front page of the website www.dovecot.org says: "it uses several coding techniques to avoid most of the common pitfalls" So I hope it is OK to follow the spirit of that with some suggestions. The two issues I encountered both seem to be fairly easy holes to fall into, and yet equally easy to avoid in the first place by using established C practices. Firstly, many 'if' statements having a single statement (whether in then or else part) are currently written in a short-cut fashion: if (condition) statement 1; else statement 2; This, though technically legal, is potentially lethal when inserting (say) debugging statements. Without diligence it is all to easy to produce: if (condition) debug 1a; statement 1; debug 1b; else debug 2a; statement 2; debug 2b; A simple edit that looks, layout-wise, as if it would do the right thing (and do in Python!); but actually radically changes the execution flow. (This is left as an exercise to the reader... to demonstrate the point.) Could I suggest that the relevant brackets be always used as a matter of course? Something like: if (condition) { statement 1; } else { statement 2; } Then the insertion of debug statements doesn't inflict surprise. (No, I didn't fall into this hole. But it is a trap waiting to happen.) Secondly, code duplication. To give one example: 'get_var_expand_table()' appears in both 'deliver/deliver.c' and 'master/mail-process.c'. (There is also a similar looking function in 'auth/auth-request.c'.) Perhaps consideration should be given to merging such instances. For instance, my woes with "%i"-expansion being treated differently in mail-reading and mail-delivery would likely never have arisen if common code had been used. I hope that helps (constructively!). Best wishes. -- : David Lee I.T. Service : : Senior Systems Programmer Computer Centre : : Durham University : : http://www.dur.ac.uk/t.d.lee/ South Road : : Durham DH1 3LE : : Phone: +44 191 334 2752 U.K. :

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[Dovecot] rc7 crashing under heavy load
by Jeff A. Earickson 08 Oct '06

08 Oct '06

Help! Our students are back and they are pounding my dovecot server to death (ie "Login process died too early - shutting down" or "too many open files" type crash). I've had my third crash today. My setup: Solaris 10, imap and imaps, 3K users coming in via horde webmail. My current connection settings are: login_max_processes_count = 2048 login_max_connections = 4096 Q: Does raising these limits actually make my problem worse or better? Are there any other variables that I should change to prevent the "too many open files"? Suggestions? Jeff Earickson Colby College

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[Dovecot] sent message not always saved in imap sent folder
by Ian Mortimer 08 Oct '06

08 Oct '06

Users who have their sent folder on the imap server report that sometimes a sent message is saved locally instead of on the server. This is the error from evolution: Error while performing operation. Failed to append to whoever@imap.server:Sent: Server unexpectedly disconnected: Unknown error Appending to local `Sent' folder instead.. We're seeing this with more than one client: evolution (linux) and thunderbird (OS X). It only happens occasionally but often enough to be annoying. It could be because the user's Sent folders are in their home directories which are NFS mounted. Are there any dovecot settings which might help? Thanks -- Ian

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[Dovecot] Lost email (inbox) TWICE
by Sezer Yalcin 08 Oct '06

08 Oct '06

I have been losing my inbox. It happened twice. (2 days ago and just half an hour ago) I am using RHEL 4.0 with dovecot-0.99.11-4.EL4 System uses sendmail + procmail, dovecot is up and running. Here is how it happened: I was using Mozilla Firefox with IMAP. At the same time, I logged in from Squirrel Webmail in IMAP to the same account. Squirrel mail did not show my inbox contents. And I turned back to Thunderbird and it said, ' an error has occurred and logged to system log' and INBOX WAS LOST! squirrelmail 1.4.6 and mozilla thunderbird version 1.5.0.7 I checked server log, I see I log in but there are no further logs. This happened 2 days ago, I was wondering what the hell happened. I did not have any issues before. However recently we had a hard drive crash and all home folders are restored from backups. I assume it can be related to this. My inbox and imap folders are all in mbox format. I believe dovecot could not write to log or had something unexpected which lead to loss of inbox. There were no configuration issues and all mail system including dovecot were working fine. Now it works fine as well, but I believe it will lose inbox folder again. Has anybody experienced this? Any suggestions to recover inbox? File was reset to 0 bytes (could be deleted as well), when i did 'stat' on file, there was a file with 1 new message, all were lost. Thank you. Sezer

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[Dovecot] Dovecot hang
by Catalin Constantin 08 Oct '06

08 Oct '06

Hello, We run dovecot 1.0.rc6-1 on a debian system. The user auth db is postgresql and the storage folders are on a NFS partition. Latelly every 2 days the authentification hangs and i see in the logs: Sep 21 10:04:22 c005 dovecot: login: tried to change state 0 -> 17808 (if you can't login at all, see src/lib/fdpass.c) What is the problem ? What can i do ? Thank you ! -- Catalin Constantin Bounce Software http://www.bounce-software.com http://www.cabanova.ro

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Re: [Dovecot] LIST command ignores "hidden=yes" for default namespace
by Bill Boebel 08 Oct '06

08 Oct '06

On Sun, August 6, 2006 7:57 pm, Timo Sirainen <tss(a)iki.fi> said: > On Wed, 2006-07-05 at 12:04 -0400, Bill Boebel wrote: >> On Sun, June 11, 2006 1:51 pm, Timo Sirainen <tss(a)iki.fi> said: >> > On Mon, 2006-05-08 at 22:03 -0400, Bill Boebel wrote: >> >I'm not sure if this is a bug or just an undesirable feature, but when I >> >have our namespace configured to match Courier's "INBOX." functionality, >> >Dovecot forces me to also define a default namespace (with no prefix). >> >Without the default namespace defined I get "NO Unknown namespace." errors >> >when trying to subscribe or unsubscribe folders. >> > >> > It was a bug when tb-extra-mailbox-sep workaround was enabled. Fixed: >> > http://dovecot.org/list/dovecot-cvs/2006-June/005709.html >> > >> >> The second part of this still seems to be the case with RC2... the LIST command >> ignores "hidden=yes". > > hidden=yes only means it's not listed in NAMESPACE command's reply and > that the namespace prefix isn't shown as a mailbox in LIST replies. > Since the prefix is empty and you're listing the mailboxes from root, it > shows the mailboxes as it should.. > > Correct way would be to just use one namespace and fix the problems > related to it. Could you test with RC6 and show me what commands give > the unknown namespace errors? Subscribing and unsubscribing worked fine > with me. Although INBOX subscription causes some problems with LSUB. > I finally got around to testing this. I tested with RC7 CSV 20060924. And I am testing with just one namespace: namespace private { separator = . prefix = INBOX. inbox = yes } I no longer get the unknown namespace errors. However, INBOX is listed twice in the LIST command: 2 list "" "*" * LIST (\HasChildren) "." "INBOX" * LIST (\HasChildren) "." "INBOX.RSS" * LIST (\HasNoChildren) "." "INBOX.Sent" * LIST (\HasNoChildren) "." "INBOX.Test" * LIST (\HasNoChildren) "." "INBOX.spam" * LIST (\HasNoChildren) "." "INBOX.Trash" * LIST (\HasNoChildren) "." "INBOX.Drafts" * LIST (\HasNoChildren) "." "INBOX" * LIST (\HasNoChildren) "." "INBOX.RSS.Kevin Minnick" If I change the namespace's inbox setting to "inbox = no" it only lists the INBOX once, however subscribing to the INBOX gives the "Unknown namespace." error. 2 list "" "*" * LIST (\HasChildren) "." "INBOX" * LIST (\HasChildren) "." "INBOX.RSS" * LIST (\HasNoChildren) "." "INBOX.Sent" * LIST (\HasNoChildren) "." "INBOX.Test" * LIST (\HasNoChildren) "." "INBOX.spam" * LIST (\HasNoChildren) "." "INBOX.Trash" * LIST (\HasNoChildren) "." "INBOX.Drafts" * LIST (\HasNoChildren) "." "INBOX.RSS.Kevin Minnick" 2 OK List completed. 4 subscribe INBOX 4 NO Unknown namespace.

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[Dovecot] Using NFS - which OS would you chose
by Jonathan 08 Oct '06

08 Oct '06

Hi, I'm still looking at a large (under 100,000) user deployment of Dovecot, with a NetApp NFS server as the back-end storage. I've read a few remarks about needing the latest NFS patches from Trond Myklebust to prevent lock-ups. My management would be happiest with a vendor-supported distribution (and especially Suse Linux Enterprise Server 9 or 10). We will be running on an x86 platform. Under these circumstances, which operating system/distribution would you choose? And why? Suse SLES9 OpenSuse Debian RedHat FreeBSD Solaris_x86 Nexenta (www.nexenta.org) Many thanks for your thoughts/war stories. Jonathan.

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