March 2007 - dovecot - dovecot.org

[Dovecot] imaptest updates
by Timo Sirainen 13 Mar '07

13 Mar '07

I spent the last 5 hours or so updating my imaptest tool. It's beginning to become almost like a real IMAP client. http://dovecot.org/tools/imaptest10.c contains a version that compiles against Dovecot v1.0 (instead of against CVS HEAD). imaptest is this tool that I've been using for a few years to do stress testing. It can create a lot of dummy IMAP client connections which execute some commands. Today I added some new features to it: - Support for pipelining commands (where allowed by IMAP spec). Looks like it about doubles the throughput. "no_pipelining" option disables this. - Support for MULTIAPPEND extension. When multiple mails are APPENDed one after another this extension is used to save them all in one transaction. - Previous versions gave an error when trying to append large mails. Now large mails work too. - By default the commands are executed in one specific order. Using "random" option randomizes the order. - You can separately specifify probabilities of how often to execute each command. 0 means never, 100 means always, 10 means 10% of the time and so on. 100,30 means that it's always executed, and then it's executed again and again with 30% probability. The basic way to run it is: ./imaptest user=test pass=password host=imap.domain.org mbox=/home/user/mail/dovecot clients=1 Or if you want to run multiple users, you can use user=test%d which will use users test1..test100 (the size is hardcoded in USER_RAND define). If you want to do benchmarking, you can set it to run for specified amount of time, and you should also give random number generator the same seed every time: ./imaptest seed=123 secs=300 If you want to test/benchmark only the login+logout speed, use: ./imaptest - select=0 To create a lot of long-running clients doing STATUS and NOOPs: ./imaptest clients=100 - logout=0 status=50 noop=50 delay=100 To test copying messages: ./imaptest copybox=Trash By default LOGIN command is used. If you want to try AUTHENTICATE: ./imaptest auth=100 Hmm. I guess that's about it. The list of commands that you can use starts from line 134. You can use either the long names or the short names.

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[Dovecot] Timed Out or Disconnect Errors on emails with attachments
by Tudor Holton 13 Mar '07

13 Mar '07

Hello all, I've migrated our Maildir system from Courier-IMAP-SSL to Dovecot with SSL and now we're getting "Connection to <server> Timed Out" errors when sending mail with attachments. The mail gets sent, however it doesn't save the mail in the user's "Sent" folder. Our IMAP and SMTP servers are different. So the client sends to the SMTP server first, completes that, and then opens a channel to Dovecot and dovecot appears to receive the data (TB gives a progress bar as it's sending to dovecot) and then disconnects _after_. We have a mixed bag of clients here from Thunderbird on Linux and Windows, through Outlook Express to Outlook. All show similar errors. I enabled the logs on dovecot, however it wasn't very informative. At the time it occurred the only line in the log file was: dovecot: 2007-03-13 16:21:12 Info: IMAP(tudor): Disconnected This is obviously different from "Disconnected: Logged out". Emails without attachments behave ok, it only occurs with emails with attachments. Has anyone else had any experience of this? Cheers, Tudor.

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[Dovecot] Prayer, Maildir and Folders whose names begin with "."
by Mike Brudenell 13 Mar '07

13 Mar '07

Greetings - I think I've just had one of my fears confirmed: not Dovecot-specific exactly, but it affects how we will use of Prayer (Webmail Software) with Dovecot... Currently our production service uses MBX-format mailboxes with the UW IMAP server; we also use the University of Cambridge "Prayer" software for Webmail. By default Prayer saves its preference settings, address book and so on in a regular IMAP folder called ".prayer" And one of the nice things about the UW IMAP server is that you can tell it not to include files whose names start "." when returning the list of folders for a LIST command. This means: * People don't see the secret ".prayer" folder when they look at the list; * But if something (eg, Prayer) knows its name it can open this folder to get at its content. The combination of these is that (a) Prayer can store its settings and (b) users don't see where, so can't open/tamper with the secret settings folder for Prayer. But I've just discovered that I can't create a folder called ".prayer" using Maildir-format mailboxes. The problem appears to be the leading "." I suspect it's because the Maildir++ specification at http://www.inter7.com/courierimap/README.maildirquota.html says this: > Folders are created as subdirectories under the main Maildir. The name of > the subdirectory always starts with a period. For example, a folder named > "Important" will be a subdirectory called ".Important". You can't have > subdirectories that start with two periods. A folder named ".prayer" would lead to a subdirectory being created called "..prayer" I think. Q. Can anyone confirm that you can't create Maildir folders called ".somename"? Q. Are there any other Prayer users out there using Dovecot and Maildir format mailboxes? What are you doing about the user-settings folder for Prayer? (And do you manage to hide it from view, so they can't tamper with its contents?) Cheers, Mike B-) -- The Computing Service, University of York, Heslington, York Yo10 5DD, UK Tel:+44-1904-433811 FAX:+44-1904-433740 * Unsolicited commercial e-mail is NOT welcome at this e-mail address. *

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[Dovecot] error with virtual users
by Antonio Casado Rodríguez 13 Mar '07

13 Mar '07

Hi, In my dovecot-deliver.log i have this: deliver(xxuser): Mar 13 11:36:49 Error: open(/home/xxuser/.temp.alboran.24421.63c6890e35b613e8) failed: No such file or directory deliver(yyuser): Mar 13 11:38:29 Error: open(/home/yyuser/.temp.alboran.26046.dcb46511eeb37f3d) failed: No such file or directory but i haven't homedir user. I have /var/spool/mail/xxuser/ maildir Is that a error? I have Dovecot-1.0-rc19 + dovecot-deliver + rhel 4.4 Thanks you

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[Dovecot] index performance issues
by Netserve 13 Mar '07

13 Mar '07

Running 1.0.rc22 We have a single file server, running NFS (Single large sas disk) with about 80Gb of mail. mount -o remount,rsize=2048,wsize=2044,actimeo=0,soft,rw xx.xx.xx.xx:/mailboxes /nfs1 There are 3 front end pop/imap servers using an LVS director. Indexes are stored on each front end server. -rw------- 1 admin 500 144 Mar 12 17:47 dovecot.index -rw------- 1 admin 500 10272 Mar 12 17:47 dovecot.index.cache -rw------- 1 admin 500 120 Mar 12 17:47 dovecot.index.log Normally everything runs fine, there are about 1500 active pop accounts and 100 Imap. Typically, 10 to 20 pop accounts are downloading at anyone time, and there may be 10 or 20 active Imap sessions. If we find that the index partition has got to 100% full and corrupted the indexes then we'll delete the entire index dir and let dovecot rebuild all the indexes however, we end up with 100mbit / 10Mb/sec of network traffic between the NFS server and the pop/imap servers. The nfs server load climbs to 20+ as does the load on the front end mail servers. It can take 4 or 5 hours for the indexes to rebuild during which time imap is slow but works and pop downloads all end up with dead processes that need clearing every few minutes. admin 5869 0.0 0.1 4384 1060 ? D 17:56 0:00 \_ pop3 [info@.co.uk 180.98] admin 5877 0.0 0.1 4392 1112 ? D 17:57 0:00 \_ pop3 [bro94 62.182] admin 5879 0.0 0.1 4396 1052 ? D 17:57 0:00 \_ pop3 [spamcatch@.com 81.163] admin 5884 0.0 0.1 4392 1056 ? D 17:57 0:00 \_ pop3 [ctaylor@.com 81.175] Normally the nfs server delivers possibly 200Kbytes of traffic average spiking to 400Kbytes but the 900+Kbytes per second sustained rate for 5 or 6 hours is killing the service. Is there something we've got wrong here? (I know a Scsi raid NFS would help as would Gbit networking but I can't see the setup we've got as needing that sort of hardware spec?) Thanks John

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[Dovecot] imap + unmounted home disk
by T. Horsnell 13 Mar '07

13 Mar '07

dovecot 0.99 still (RHEL4), I'm sorry to say. The config is for mbox's to live on the user's home disk. If the user tries to make an imap connection when his home disk is unmounted, various permission denied messages are logged, as expected, but then the imap process seems to hang around instead of aborting. The result is that eventually the imap process limit is reached, and even those users whose home disks are correctly mounted, cant get at their mail. Apologies if this has already been fixed - I cant find anything relevant in the archives. Cheers, Terry

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[Dovecot] Password encoding
by David Mills 13 Mar '07

13 Mar '07

Hi, I've currently got a problem authenticating to my dovecot server (1.0rc15). The server is set up to authenticate against a mysql server, with a default password scheme of 'crypt'. The problem is that some of the passwords I need to transfer (all from /etc/shadow files) are md5 encoded, and when I put {md5-crypt} in front of the password to force the scheme, dovecot answers :"Unknown password scheme md5-crypt". If anyone has any ideas, I'd really appreciate it. TIA for your time. David -- David Mills Enki Technologies 01 76 00 71 20Unknown password scheme md5-crypt *De nouveaux sites voient le jour...* *...avec GenieBuilder !* Site de Vico <http://www.vico.fr> - enki.fr <http://www.enki.fr>

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[Dovecot] Problems fetching mail
by Curt LeCaptain 13 Mar '07

13 Mar '07

I'm attempting to replace UW-IMAP with Dovecot, as my UW-IMAP implementation seems to be not working very well. Here's the problem I had with UW-IMAP: In Horde/IMP, messages just wouldn't appear at all. If I opened up the user's IMAP box via an IMAP client, I'd get a Bogus sequence in UID fetch error. So, now I've got Dovecot in place, and I'm getting the following error upon attempting to look at this same box: Error in IMAP command UID: Invalid UID messageset. Now, this user has 3 messages, each X-UID increments by one, starting at 1, so: X-UID: 1 X-UID: 2 X-UID: 3 None of those seem out of the ordinary size wise. I'm not sure what config information you'll need of me, as I'm new to dovecot, but any help would be appriciated. Thanks, Curt L.

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[Dovecot] Quota and Trash
by Bernhard Schmidt 12 Mar '07

12 Mar '07

Hi, I finally got a grip on our mail guys to try out Dovecot after they started migrating a ~15k user mailsystem to Maildir+NFS (Netapp)+Courier and the performance was not as good as expected. So far the results are impressive, although there are of course a few small issues to be solved. One is the current Quota handling, which they use with Courier IMAP and (still) think it needs to be replicated 1:1 to dovecot. Currently they use maildir++ quota format. Mails moved to Trash get not included in the Quota calculation (standard "feature" of Courier IMAP) and get expunged after a certain period of days (IMAP_EMPTYTRASH). Is there any way we could replicate this behaviour with Dovecot? Not including mails in the Trash-folder into quota calculation seems to be a no-go to me according to the documentation, you can ignore the quota limit when copying messages into a certain folder with the "ignore" keyword but they are still included. This issue is directly related with the second one. Deleting old mails in Trash could be archieved with the expire-plugin, but that does not work with Dovecot v1.0, and I'd definitely want to run this. So I have to use "find", which deletes the mail from the folder. However, those mails are still included in the Quota calculation, so that will very likely become incorrect. Is there a generic recommendation for a tool that could be used to rebuild maildir quota calculations? Any other ideas how I could solve this problem and have dovecot behave like Courier here? Thanks, Bernhard

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[Dovecot] Search not working?
by Marc Perkel 12 Mar '07

12 Mar '07

I switched for mbox to maildir last night and now searching folders isn't working. Getting a timeout. Is there something I might have forgot to configure?

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