- dovecot - dovecot.org

[Dovecot] global vs user script
by M1 15 May '07

15 May '07

What is the order of execution if both user and global sieve script exists? Thanks.

4 10

[Dovecot] Mails, work and so on
by Timo Sirainen 14 May '07

14 May '07

You can probably guess from my flood of mails that I'm no longer busy. I still have a couple of exams but since I haven't spent any time at all studying for them or attending the lectures, I can just as easily leave them for next year. I've read and answered most of the "easy" mails in this list and in my INBOX. I'll try to answer the rest of them this weekend, so no need to forward them to me again, at least not yet. :) Now that I'm finally non-busy, it also appears that I haven't worked for a long time and I'm almost broke. :) So now would be a great time for your corporation to buy/sponsor some Dovecot development. Otherwise I'm probably soon busy with non-Dovecot related work. My own high priority TODO contains: - Get the rewritten Squat full text search index working. It probably needs a name change, since it's not all that close to Cyrus Squat anymore. Suggestions? Could of course be just "fts_dovecot". - Shared mailboxes / ACLs - dbox cleanups and possibly partial redesign. I'll write a separate mail about this later. - Index file code cleanups, simplifications and optimizations. Make it work with NFS with attribute cache enabled.

5 7

[Dovecot] How to get rid of locks
by Timo Sirainen 14 May '07

14 May '07

Although Dovecot is already read-lockless and it uses only short- lived write locks, it's be really nice to just get rid of the locking completely. :) I just figured out that O_APPEND is pretty great. If the operating system updates seek position after writing to a file opened with O_APPEND, writes to Dovecot's transaction log file can be made lockless. I see that this works with Linux and Solaris, but not with OS X. Could you BSD people try if it works there? http://dovecot.org/ tmp/append.c and see if it says "offset = 0" (bad) or non-zero (yay). The O_APPEND at least doesn't work with NFS, so it'll have to be optional anyway. Currently Dovecot always updates dovecot.index file after it has done any changes. This isn't really necessary, because the changes are already in transaction log, so the dovecot.index file can be read to memory and the new changes applied on top of it from transaction log (this is pretty much how mmap_disable=yes works). So I'm going to change this to work so that the dovecot.index is updated only if a) there are enough changes in transaction log (eg. 8kB or so) and b) it can be write-locked without waiting. Maildir then. It has this annoying problem that readdir() can skip files if another process is rename()ing them, causing Dovecot to think that the message was expunged. The only way I could avoid this by locking the maildir while synchronizing it. Today I noticed that this doesn't happen with OS X. I'm not sure if I was just lucky or if there really is something special implemented in it, because it doesn't work anywhere else. I'm not sure if this is tied to HFS+, or if it will work with zfs also (Solaris+zfs didn't work). So perhaps the locking could be disabled while running with OS X. More importantly I figured out that it can also be avoided with Linux +inotify. As long as the inotify event buffer doesn't overflow, the full list of files can be read by combining the readdir() output and files listed by inotify events. If the inotify buffer overflows (highly unlikely), the operation can just be retried and it most likely works the next time. So with these changes in place, changing a message flag or expunging a message would usually result in: - lockless write() call to dovecot.index.log - lockless read()ing (or looking into mmaped) dovecot.index.log to see if there's some new data besides what we just wrote that needs to be synchronized to maildir - rename() or unlink() calls to maildir. If a call return ENOENT, the maildir needs to be readdir()ed with inotify enabled to find the new filename. Not a single lock in the operation, assuming that dovecot.index file wasn't updated. Assigning UIDs to newly delivered mails would require locking though. dovecot-uidlist needs to be locked, and the UIDs need to be written to dovecot.index.log file in the correct order, which can also be done with dovecot-uidlist locking. Actually a single write() to dovecot.index.log isn't enough. I think there needs to be some kind of a flag written to the beginning of the transaction which marks the transaction as truly finished. If the flag isn't there, any reader knows to stop and wait until the flag is set. So this means that the writer needs to: 1. Do a single O_APPENDed write() call writing the whole transaction 2. Get the current offset with lseek(fd, 0, SEEK_CUR) (this is what the append.c tester checks) 3. pwrite() the finished-flag to beginning of the transaction Except at least with Linux pwrite() doesn't work if O_APPEND is enabled. There are two ways to work around this: a) fcntl(disable O_APPEND) + pwrite() + fcntl(enable O_APPEND) b) Keep two file descriptors open for the transaction log. First with O_APPEND flag and second without. pwrite() to the second one. a) is probably better because it doesn't waste file descriptors.

8 10

[Dovecot] PATCH: sendmail-like DSNs in Dovecot deliver (EX_TEMPFAIL always)
by Steffen Kaiser 14 May '07

14 May '07

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hello, I've put together an always tempfail & sendmail-like DSN report back patch. Because I don't know how to transform the rejection reason into sysexit.h codes, it always tempfails. The hooks are so that: a) config file setting: lda_mode = mode b) command line: deliver --mode mode where mode is default or sendmail. When no mode is specified, it defaults to "default", which is the current behaviour. In sendmail mode, mail_send_rejection() simply prints the rejection reason to stdout, logs it and returns EX_TEMPFAIL. Ideally, the return value would be specific to the reason. I haven't poked into this deeply, but it doesn't look straight forward. Bye, - -- Steffen Kaiser -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iQEVAwUBRkHNQS9SORjhbDpvAQIhdggAq79RHKa1gIUTFwAu7Gd2maIUkDTgbNu6 8+MEQHujOPkV6wcF+5ih/hkht5BnuBUiIbnp2dvKGaUcHY8avzYD6BEc6gIAyJjM YIKDANI5+BVnQWUdiQMlQrSrRIZBqFziL8v/LvICJUsiOqCKT7se37KuUOK14gXO FSghuPta0rorogJ8kh+VGdmnqNVzKb6eKrnFQUggiezTmTcHY6/DRsLbsKV//fyW cybualj+THF9cj+EajwCMsYypc9KOdVg6lhcCD87oskDmMqcG5lwF2HU9nclnMxE 6pOnaLGNfKmWyeAKOLgvMimjhkU74+NBwQ+b4h61JzZ6lbiZKWX7wA== =gE8Z -----END PGP SIGNATURE-----

3 5

[Dovecot] PATCH Deliver forgets sendmail_path if DEBUG is set
by Steffen Kaiser 14 May '07

14 May '07

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hello, Dovecot v1.0.0 deliver erases the environment if DEBUG is set, hence, also (probably) erases SENDMAIL_PATH if it has been read from configuration file. This happens with: Debian Etch, libc-2.3.6.so, gcc (GCC) 4.1.2 20061115 (prerelease) (Debian 4.1.1-21). Problem in log: May 10 12:33:07 ux-2s11-9 deliver(dvtest): execv() failed: No such file or directory May 10 12:33:07 ux-2s11-9 deliver(dvtest): Sendmail process terminated abnormally, exit status 75 Note the empty string in the function call execv(). Attached patch just deletes the DEBUG variable. Bye, - -- Steffen Kaiser -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iQEVAwUBRkL45y9SORjhbDpvAQKeTAgAr6i6XrICqZsTaezUFqXO69cuwOt4iL5u K3PAF0ywAtrRkpWG+G8TUtypUkLp+CGEK3Ery1mWVp2/TeNPv6LxeUWWGxmdlSV3 XFQSV/VRuPtJ/Uc8wFWOBcpAn0H9rnLNkF5vv512t4zs99eF10++US5fZwFOXK8M azgaCEYwOrmZ4U2sCQwVQChXcZQq6MI5IcE3ChpzlUP45bq2dVZrXqAZ/xNo1iuG lQd/43XJu1++LxB8N1Fkbaeme+Ojt/c5fOKApjhnCJuQwi46jnSEeHbO2VUCz+ST mU34QR3zx+h4YW91oKQhFYkbSWEYmuXk2OoZaFUd1Q+E+oXHHuDBng== =CiqO -----END PGP SIGNATURE-----

2 2

[Dovecot] header-lines of subfolders have to be rescanned after each client startup
by Rainer Sigl 14 May '07

14 May '07

Hi all, after each startup of my different mail clients (thunderbird, outlook, ...) the contents of subfolders if I click in has to be renewed. This takes some time for large folders. I just migrated from courier. And there all subfolders were available immediately. Is there something to configure? Another effect regarding subfolders is that the client forgets, which subfolders were opened after shutdown and shows the folders closed. This means, that necessary subfolders have to be reopened after each startup. This was managed as well by my previous courier server. Many thanks for answers Rainer Sigl -- ----------------- Rainer Sigl, | email: sigl(a)mpe.mpg.de MPI f. extraterrestrische Physik, | phone: +49 (89) 30000-3557 Postfach 1312, | fax: +49 (89) 30000-3569 D-85741 Garching, Germany | web: http://www.mpe.mpg.de/~sigl/

2 4

[Dovecot] v1.1 plans
by Timo Sirainen 14 May '07

14 May '07

I think I won't do any actual releases until it's mostly feature complete. Then maybe v1.1.alpha1 or v1.1.beta1. So if you want to test it before then, use CVS or the nightly snapshots. I'm planning on keeping v1.1 almost completely compatible with v1.0. There could be some minor configuration file changes, but for most people v1.0's dovecot.conf should work with v1.1. I want to update index file handling to use less locks and update dovecot.index file less often. The file formats would still stay backwards compatible with v1.0. After this I'm hoping to get index files working well with NFS even with attribute cache enabled. Dovecot v2.0 then brings incompatible index files and more or less rewritten configuration file handling. It could still support old config file format and settings, but the default will be somewhat different. I'm hoping to release the first alphas/betas in 2-3 months, with v1.1.0 maybe even as early as next summer. The good thing here is that index file code hasn't changed much since v1.0, so it should be stable. The bad thing is that I've added a couple of completely new indexes. I'm also quite busy for the next month, but I'm not sure how much it affects my coding. :) The largest already implemented new features are: + Added support for IMAP UIDPLUS extension + IMAP SORT: Sort keys are indexed, which makes SORT commands faster. + IMAP THREAD: Threads are indexed into a dovecot.index.thread file. It can usually be updated incrementally, so this makes THREAD fast. + Added Dovecot-specific X-REFERENCES2 threading algorithm. It's similar to REFERENCES, but it doesn't do base subject merging and it sorts the threads by their newest message. + When saving messages, update cache file immediately with the data that we expect client to fetch later. Maildir-only currently. + Mailbox list indexes. Mailbox metadata is stored there, so STATUS commands can return synchronized mailboxes' metadata simply by reading a single mailbox list index file. - FIXME: Currently works only with Maildir++ layout. + Expire plugin can be used to keep track of oldest messages in specific mailboxes. A nightly run can then quickly expunge old messages from the mailboxes that have them. The tracking is done using lib-dict, so you can use either Berkeley DB or SQL database. + Namespaces are supported everywhere now. - FIXME: except by convert plugin + Full text search indexing support with Lucene and Squat backends. + OTP and S/KEY authentication mechanisms (by Andrey Panin). + mbox and Maildir works with both Maildir++ and FS layouts. You can change these by appending :LAYOUT=maildir++ or :LAYOUT=fs to mail_location. Features that I'm planning on implementing: - Fully supported shared mailboxes and IMAP ACL extension - Replace Squat FTS indexes with my new design - Case-insensitive searches with non-ASCII text as well - Maybe add support for all kinds of IMAP extensions that can be easily supported. LEMONADE extensions especially: CONDSTORE, CATENATE and maybe even URLAUTH if I can figure out how it should work. If a feature can be implemented completely as a plugin, it could still come in v1.1.beta stage, because it won't destabilize the rest of the Dovecot anyway.

17 36

[Dovecot] Feature Request: content-filter / MOVE scripts
by Daniel L. Miller 14 May '07

14 May '07

Since your "1.1 plans" announcement somehow turned into everybody handing in a wish list . . . thought I'd start one by itself - since I expect a few people to have opinions on this matter. I'm aware of a plug-in functionality in Dovecot, and that a plug-in exists for dspam processing - but my review of the plug-ins indicate they require compiling your own Dovecot - the plug-in setup isn't really suitable for packaged distros. As a packaged software user - I really really really don't like compiling my own software, either for features or bugfixes - I want leave that to the experts. On learning of 1.0's official release, I nudged the Debian package maintainers to check - and they were already on it and it updated. Thanx Timo, Jaldhar, and Fabio. I have some thoughts on an interface that would eliminate the need for compile-time plug-ins, but provide some major power to sysadmins. Basically, I want a way of telling an external program the following: 1. A message was moved. 2. The folder is moved from was XXX. 3. The folder it moved to was YYY. 4. The message moved was ZZZ. Armed with this information, just about anybody's spam fighting learn scripts can be called to do their thing. A few different ways have occurred to me: 1. Have a dedicated "content-filter" functionality built-in to Dovecot. Under this model, Dovecot.conf would include at least three new parameters: FILTER-FOLDER-SUFFIX, FILTER-FOLDER-IN-SCRIPT, and FILTER-FOLDER-OUT-SCRIPT. Whenever a message is moved into or out of a folder ending in SUFFIX the appropriate SCRIPT is called, with the arguments above being passed. 2. A bit more generic, less processing for Dovecot. Dovecot.conf parameter ACTION-SCRIPT (hey, feel free to use other names - I'm just brainstorming here). Any time any message is moved anywhere, call SCRIPT with the arguments. Having never looked at Dovecot's code, I'm just guessing, but this probably wouldn't take much to implement - but might be the most performance affecting. 3. Have a definable named-pipe to send the same information to. 4. Have a definable TCP socket to send the same information to. In any case, I figure it's best to prevent any message processing by Dovecot itself - so while it might be nice to define a list of headers to send to the scripts, instead of the whole message, that's probably not appropriate for Dovecot to focus on. On the other hand, any of the above options would probably benefit from a MAXIMUM_FILTER_SIZE parameter to limit the maximum message size. So what's the world got to say about this? (More importantly, how does TIMO feel about this?) ;). -- Daniel

3 2

[Dovecot] Dovecot, Postfix and SMTP AUTH....
by Bartosz Toczek 13 May '07

13 May '07

Hello. I've notice a problem with SMTP AUTH in postfix with dovecot. My configuration is based on Postgresql. I've created a function in postgresql which returns password and username and attached it to password_query. Query looks like this password_query = SELECT username_out as username, password_out as password FROM get_password(lower('%n'),lower('%d')); Problem is when get_password returns something like this... vmail=# SELECT username_out as username, password_out FROM get_password(lower(''),lower('')); LOG: statement: SELECT username_out as username, password_out FROM get_password(lower(''),lower('')); LOG: duration: 2.342 ms statement: SELECT username_out as username, password_out FROM get_password(lower(''),lower('')); username | password_out ----------+-------------- | (1 row) It returns 1 empty row.... When this is attached to postfix with smtp auth with such configuration # SMTP AUTH broken_sasl_auth_clients = yes smtpd_sasl_auth_enable = yes smtpd_sasl_security_options = noanonymous smtpd_sasl_authenticated_header = yes smtpd_sasl_local_domain = smtpd_sasl_type = dovecot smtpd_sasl_path = private/auth my serwer starts to be open relay... I now that it returns empty string for username and password... so where is the password checked... if I dont send password as a parameter to my function. Definition of the function looks like this: CREATE FUNCTION get_password("login" character varying, "domain" character varying, OUT username_out character varying, OUT password_out character varying) RETURNS record Can you help with that... BT ---------------------------------------------------------------------- Zrob numer kumplom >> http://link.interia.pl/f1a5d

4 4

[Dovecot] Public folders using NAMESPACE
by Joakim Ryden 13 May '07

13 May '07

Howdy folks! I've been trying to research how to (or if possible at all) implement public folders using the namespace feature on a server with multiple virtual domains. After about an hour of looking around I'm a little confused. :) I guess there are two questions: 1) Is it possible / does it work? 2) If yes, does anyone have a sample configuration or write-up of How You Did It[TM] to share? I've been mainly focusing on the thread from here: http://www.dovecot.org/list/dovecot/2006-June/013683.html and the wiki ACL documentation: http://wiki.dovecot.org/ACL but I'm having a hard time piecing it all together... Thanks for any and all tips! --Jo

2 5

[Dovecot] mailquota in ldap attribute 'mailQuota'
by Shahmat Dahlan 13 May '07

13 May '07

I've tried having the ldap quota in an ldap attribute, which still doesn't work. /etc/dovecot.conf protocols = imap pop3 mail_location = maildir:/data/mail/%u/Maildir protocol imap { mail_plugins = quota imapquota } plugin { quota = maildir:ignore=Trash } the rest are defaults added an attribute 'mailQuota' with value '10240' kbytes or 10Mbytes as for /etc/dovecot-ldap.conf user_attrs = mail,homeDirectory=home,uidNumber=uid,gidNumber=gid,quotaStorage=mailQuota Would appreciate if anyone could assist on this. I'd prefer to use the above than setting the mail quota manually: quota = maildir:storage=10240:ignore=Trash We are actually in the planning stage of migrating all of current our mailboxes from Netscape to Dovecot, instead of upgrading it to those new Sun.

2 1

[Dovecot] Deferring, instead of rejecting, messages when at quota
by Mike Brudenell 13 May '07

13 May '07

Greetings - I'm having trouble working out where to alter this behaviour (so please forgive me if it turns out to be an Exim thing rather than Dovecot!)... My test service is using Exim as the MTA and Dovecot's "deliver" for the LDA. We are using Maildir mailboxes with filestore quotas. When I send a large test message to myself that cannot be delivered because I don't have sufficient available quota remaining an error message is immediately returned to the sender and the incoming message discarded. The error message says this: Your message was automatically rejected by Dovecot Mail Delivery Agent. The following reason was given: Not enough disk space Instead of Exim rejecting the incoming message and generating the error response because of deliver's failure to, umm, deliver I'd like the message to be retained in Exim's queue so that it can be retried periodically. With our old/live system (Sendmail + UW IMAP's "tmail" LDA) I edited the tmail source code to return a different exit code: one that caused Sendmail to defer (re-queue) the message rather than reject it. How do I achieve this effect with Exim + deliver please? Is it a case of: * Setting something in Dovecot's configuration file (I can't spot what!); * Changing a return code in deliver's source (if so, whereabouts and to what?); * Or is there an Exim directive I need to add to the transport definition in its configuration file? With thanks, 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. *

3 3

[Dovecot] wierd ssl-parameters.dat regeneration error
by Kyle Wheeler 13 May '07

13 May '07

I just had a strange problem with my Dovecot 1.0 installation. After about two weeks, it logged these messages: dovecot: Error: ssl-build-param: rename(/usr/local/var/lib/dovecot/ssl-parameters.dat.tmp, /usr/local/var/lib/dovecot/ssl-parameters.dat) failed: No such file or directory dovecot: Error: child 30689 (ssl-build-param) returned error 89 And thereafter, all login attempts resulted in this: dovecot: Error: imap-login: read(ssl-parameters.dat) failed: Unexpected EOF dovecot: Error: child 19036 (login) returned error 89 Thankfully, deleting the ssl-parameters.dat file (/var/run/dovecot/memoryhole.net/login/ssl-parameters.dat) and restarting dovecot fixed the problem, but it seems odd to me that dovecot expects /usr/local/var/lib/dovecot to exist (because, of course, it doesn't). I'm not defining that directory in the config file anywhere. Does anyone have any idea what's going on? ~Kyle -- I'm sick of following my dreams. I'm just going to ask them where they're going and hook up with them later. -- Mitch Hedberg

2 10

[Dovecot] Mailbox creation with Spam
by Master Abi 13 May '07

13 May '07

Hi all, I got dovecot working, but I would like to know when and what creates the mailbox (cur, new, trash, etc ). I noticed that when a client connects for the first time that mailbox is created or when a mail arrives for the first time (i think). I would like to give each mailbox a Spam folder, and possibly doing this automatically. Is this possible with some dovecot setting and not via scripting. Thanks master

2 1

[Dovecot] fs quota plugin and NFS
by Nicolas STRANSKY 13 May '07

13 May '07

Hi, I'm trying to use the Dovecot v1 fs quota plugin. The server uses NFS mounted volumes for INBOX and other maildir folders. The /usr/bin/quota command is working seamlessly but I get errors with the quota plugin, which gives the following logs: Apr 19 17:46:15 rouge dovecot: IMAP(xyxyxyx): quotactl(Q_GETQUOTA, nfs.xxx.yyy.org:/home) failed: No such file or directory Apr 19 17:46:18 rouge dovecot: IMAP(yxyxyxy): quotactl(Q_GETQUOTA, nfs.xxx.yyy.org:/home) failed: No such file or directory Is there a way to get it work ? Thanks, -- Nico Il faut s'entraider, c'est la loi de nature. -+- Jean de La Fontaine (1621-1695), L'Âne et le Chien (Fables VIII.17) -+-

2 3

[Dovecot] mailquota in ldap attribute 'mailQuota'
by Shahmat Dahlan 13 May '07

13 May '07

I've tried having the ldap quota in an ldap attribute, which still doesn't work. /etc/dovecot.conf protocols = imap pop3 mail_location = maildir:/data/mail/%u/Maildir protocol imap { mail_plugins = quota imapquota } plugin { quota = maildir:ignore=Trash } the rest are defaults added an attribute 'mailQuota' with value '10240' kbytes or 10Mbytes as for /etc/dovecot-ldap.conf user_attrs = mail,homeDirectory=home,uidNumber=uid,gidNumber=gid,quotaStorage=mailQuota Would appreciate if anyone could assist on this. I'd prefer to use the above than setting the mail quota manually: quota = maildir:storage=10240:ignore=Trash We are actually in the planning stage of migrating all of current our mailboxes from Netscape to Dovecot, instead of upgrading it to those new Sun.

1 0

[Dovecot] Migrating to Maildir -> path
by Wouter de Jong 13 May '07

13 May '07

Hello, I'm in the process of migrating to Maildir, and I wondered what would be an acceptable path. I want to do virtual-accounts only, so $HOME/Maildir/ is not an option. I was thinking of /some/path/username(a)domain.tld/Maildir/ and later perhaps /some/path/(firstletter)/username(a)domain.tld/Maildir/ but perhaps Maildir/ is a bit too redundant here.... Anyone who could advice ? Many thanks, Wouter

3 2

[Dovecot] Mixing MBOX and Maildir?
by Marc Perkel 13 May '07

13 May '07

Is it possible to have some folders be mbox and some be maildir format? Why you might ask? Sometime for diagnostics I have the Exim MTA archive certain messages in MBOX format and then I want to copy them into an imao folder to look at them with Thunderbird. When I used MBOX all I had to do was copy the file into a folder and it worked. So what I'd like to do is have a folder with a special name that is MBOX and the rest be maildir. Ideally have Dovecot be smart so that if the file exists then it is assumed to be MBOX and if the directory exists then it is assumed to be maildir. Has anyone done anything like this?

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[Dovecot] Time adjusting
by Robert McKenzie 13 May '07

13 May '07

Would it be possible to have an option/variable in the config file to allow for easier setting of the maximum time to sleep for rather than having it hard coded or allow for adjustment up to an amount greater than 5 as it is at present but still have an upper limit hard coded. My system is regularly out on boot up by up to 7 seconds and consequently dovecot kills itself, if I restart it is fine and keeps going without a problem until the next reboot. Regards, Robert McKenzie. -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.467 / Virus Database: 269.7.0/801 - Release Date: 12/05/2007 18:40

4 3

[Dovecot] Writing a new mailbox access module
by Tom Alsberg 13 May '07

13 May '07

Having finished a few other projects, I'm contemplating trying to write a new mailbox module which could be useful for us here. I would appreciate any guidance. Basically, I need (or rather, could use) a module that provides a merge of two mailboxes (which are themselves accessed by other modules), cascading them, so that: * The user sees one mailbox M, which contains all the messages in the mailboxes A and B. * A and B are both already accessible by existing Dovecot mailbox access modules, but possibly by different modules (e.g. A is an mbox, B is a Maildir). * Any write operation (creation of a new message, etc.) is eventually performed on B. * As soon as a message that was in A is accessed (either for read or for write), it is transferred to B. I would use such a module to combine the spool file in /var/mail with some INBOX in the user's home directory. The incentive is the following: * Traditionally, users receive their mail in the spool, commonly in /var/spool. Mailers, like mail, elm, pine, mutt, etc. move each read message to some record mailbox (commonly ~/mbox, but with the more advanced mailers it can be configured to be some other mailbox, even a Maildir). * Users keep working this way. IMAP will not substitute the regular mail access when inside the network here. But it should be as convenient as possible to use it from the outside (e.g. at home, or from an Internet Café, or using some Webmail interface). * Mainly for administrative reasons, it is desirable that mail keeps being delivered to the spool, and not directly to the user's home directory. One of the reasons is that mail never fails to be delivered as long as there is space in the spool. When the user is out of quota on his home directory, the mail does not get rejected, and a failure only occurs when the user initiates some operation (like reading the message). Another reason is simply to be compatible with the way traditional mailers and users work. * IMAP, and IMAP clients (e.g. Thunderbird, the most common one here), on the other hand, usually do not recognize the concept of a spool. There is an INBOX, where all mail arrives, and this is where all new messages should arrive, and remain, unless they are deleted moved elsewhere. * It would of course not be desirable to just move messages automatically after the user reads them, because it would confuse users when a message suddenly disappears from a mailbox all by itself. * The best way I can think of to be consistent with both the traditional way mailers work (moving messages from spool to ~/mbox after they are read) and the way IMAP is commonly used (INBOX contains all received messages not deleted or moved, including messages that just arrived), would be using such a module as I suggested, with (using the previous terminology) e.g. M=INBOX, A=spool, and B=~/mbox. I have just skimmed again through the mailbox code (which I last looked at over a year ago, back when it was in alpha releases), not going too much into details. From past experience and current skimming, working with that code doesn't seem too straightforward, though. I can think of how to implement the logic I described on its own (i.e. as a library with a few functions), but not sure how difficult it will be to interface it with Dovecot. Is there any developer/module writer's guide somewhere that explains the mailbox access module interface? I'd appreciate some basic guidance to start with. If I get to working on it seriously, expect lots of questions from me about the code :-) Regards, -- Tom -- Tom Alsberg - hacker (being the best description fitting this space) Web page: http://www.cs.huji.ac.il/~alsbergt/ DISCLAIMER: The above message does not even necessarily represent what my fingers have typed on the keyboard, save anything further.

2 1

[Dovecot] dovecot deliver tries to setuid but why?
by Daniel 13 May '07

13 May '07

Hi! I've set up postfix(2.4.1) + dovecot(1.0-cvs) + dovecot-lda(1.0-cvs). Dovecot's deliver is running as vmail:vmail (according to postfix's master.cf). Now the problem (when receiving mail): deliver(leva): auth input: leva deliver(leva): auth input: uid=8006 deliver(leva): auth input: gid=8000 deliver(leva): auth input: home=/var/mail/virtual/leva deliver(leva): setuid(8006) failed: Operation not permitted Every virtual user has different uids, but the gid is the *same* for everyone. The gid is 8000(vmail) for everybody, and deliver runs as 8000:8000 (vmail:vmail). vmail group has write access to the users' maildirs. So why does deliver try to setuid when it has group write permission to the destination directory? Thanks! Daniel

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[Dovecot] Virtual User Home Directory, and APOP Clear Text Passwords
by imacat 13 May '07

13 May '07

Dear all, Hi. This is imacat from Taiwan. I'm new to this list. I was migrating from Qpopper to Dovecot. (Qpopper copies the mailbox when POP3 logged in, which causes quota problem.) Generally Dovecot is nice. However, I have a few questions: 1. I have a few virtual users, and I'm not using IMAP. Do I still have to give them a writable home directory? I mean, they exists only for me to receive mails from fetchmail. They really have nothing but their inbox. But if I do not give them a writable home directory, I got this error in my syslog all the time: mbox: Can't create root mail directory /home/homeless/mail: Permission denied 2. I would like to use APOP in addition to SSL/TLS. Currently Dovecot saves APOP passwords as clear text. I understand this. But is it possible to have some sort of encoding, for example, Base64? Just to prevent casual reads. I have several users. I do not want to know their passwords just to add them to the APOP database. I do not want other roots to read my passwords, intended or not. Encoded passwords also have the advantage that I can use passwords that contain the colon sign ":". It would be nice if something a little harder than Base64 can be used. Thank you very much in advance. -- imacat ^_*' imacat(a)mail.imacat.idv.tw PGP Key: http://www.imacat.idv.tw/me/pgpkey.txt Tavern IMACAT's http://www.imacat.idv.tw/ Woman's Voice http://www.wov.idv.tw/ TLUG List Manager http://www.linux.org.tw/mailman/listinfo/tlug

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[Dovecot] SASL using different auth database?
by Dave McGuire 13 May '07

13 May '07

Hi folks. Is it possible to configure Dovecot to authenticate against one mechanism (i.e., /etc/passwd) for POP/IMAP connections, while providing a SASL authentication socket that satisfies authentication requests against a different mechanism, say MySQL? The goal here is to allow users to have different passwords for SMTP authentication and POP/IMAP connections. I am converting an existing installation to Dovecot...this installation currently has quite a few users who are configured with SMTP authentication (Cyrus SASL/saslauthdb) using different passwords than are configured for their POP connections (via cucipop, /etc/passwd). If someone can think of any better way to accomplish this goal, I'm all ears. Thanks, -Dave -- Dave McGuire Port Charlotte, FL

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[Dovecot] logging IMAP size?
by Armijn Hemel 12 May '07

12 May '07

hi all, is there a way to somehow log the size of an IMAP session with Dovecot? With POP3 there is this pop3 format string I can set in dovecot.conf, but I don't see an equivalent for IMAP. If so, are there any plans to add this functionality? thanks, armijn -- --------------------------------------------------------------------------- armijn(a)uulug.nl | http://www.uulug.nl/ | UULug: Utrecht Linux Users Group ---------------------------------------------------------------------------

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[Dovecot] dbox redesign
by Timo Sirainen 12 May '07

12 May '07

I don't think anyone uses dbox currently, so the whole format could still be redesigned. So I was thinking about doing two major changes: 1. Rely on index files a lot more. The flags are already stored in index files, so there's no need to waste I/O updating them to dbox files all the time. They could still be updated (if indexes get deleted, the flags aren't all gone), but less often. 2. Require fcntl() locking. Currently dbox uses dotlocks which is slow. Cydir could be a good alternative also once index file code is made a bit more robust. Perhaps I could implement single instance attachments for cydir too.. Locking ======= The current dbox "index" file would be gone. It's pretty useless. Replace it with a whole new index file. Or perhaps it should be called "locks" file or something. The locks file would contain records: <file id> <lock timestamp> <status>. So something like: <header> 1 4645a60f 0 2 00000000 N 3 00000000 D That would mean that the first file is locked by some process, either for appending or expunging. The 2nd and 3rd files aren't locked. New messages can't be appended to 2nd file anymore. 3rd file is already deleted and this record needs to be removed when rewriting the file. Locking a dbox file for either appends or expunges is done like: 1. See if timestamp is zero - If not, see if it's older than .. let's say a day or so .. a) Yes: Continue to 2. b) No: Assume the file is locked 2. Do fcntl() byte range lock over the record line in the locks file. - If it failed, the record is locked 3. Write the timestamp. 4. Compare stat() and fstat() inodes to see if the file was rebuilt - If yes, reopen the file and goto 1 5. File is now locked. Do the append/expunge. 6. Write timestamp to zero. 7. Unlock the byte range. If a file is locked, append will try another file and expunge will mark the message as expunged instead of actually expunging it yet. Note that the locks file is read without locking. This is safe because data is never moved within the file, and it doesn't matter if the timestamp isn't read correctly always. The timestamp check is only an optimization. Actually I'm not sure if it would be better not to have the timestamp at all. Deleted records will stay in the file until the file is rebuilt. If a deleted record is noticed in the file, the process tries to lock the whole locks file. If it succeeds, it proceeds with writing the non-deleted records to a temporary file and rename()ing it over the locks file. Appending ========= 1. Find the first file in the locks file that has appendable=0 - If no such file was found, go to "create a new file" logic as described below 2. Lock the file record 3. Verify from the file's headers that this file can actually be appended to - If messages have been expunged from a dbox file, it can't be safely appended to anymore. - Other reasons include eg. configurable max. file size and daily rotations 4. Write the mail 5. Lock locks file's header 6. Get the UID from "next uid" field and update it 7. Unlock the header 8. Unlock the file record 9. Update index file Create a new file logic: 1. Create a temporary file 2. Write the messages there 3. Lock locks file's header (including fstat() / stat() rebuild check) 4. See what the latest file ID is in the file 5. rename() temp fail to msg.<latest file id+1> 6. Lock locks file for the range of the to-be-written record below 7. Write the new record to locks file 8. Go to step 6 in the original append logic Syncing / expunging =================== If locks file's header's "next uid" doesn't match the one currently in index file, the appending crashed between steps 6 and 9. Find the new message(s) and append them to index file. If the locks file is completely gone , rebuild it by going through all the msg.* files in the directory. If "expunge counter" (see below) doesn't match in locks file's header vs. index file header, go through all the msg.* files to see if a message exists in multiple files. If found, remove the duplicates. Typically neither of the above happens, so the only thing to do here is to write changes from index file to dbox files. This may mean flag changes once in a while, but most importantly expunges will always be synced. Initially figure out what files require expunging. Try to create a single lock range that includes all of them. If there are non-zero lock timestamps in that range, create multiple ranges. If a file couldn't be locked, the expunge is done by updating expunge-flag in the file. This can be done without locking (see below for flag updates). If a file was successfully locked, the expunging is done by: 1. Update "expunge offset" in file header to the offset of the first expunged message. If expunge offset is non-zero, the file is treated as non-appendable. Also when rebuilding and finding the same message from multiple files, this field is used to figure out which file should be truncated. 2. Copy the rest of the non-expunged messages to a new temporary file and add the file to locks file using the "Create a new file" logic described for appends. Instead of updating "next uid" field, update "expunge counter" field. 3. ftruncate() the old file. 4. Update "expunge counter" in index file. Sync locking ============ If there is one big "sync lock", then flags can be updated in any file with relying only on that lock. Some files may be locked, but they're locked for appends so flag updates (and other record updates as well) are safe. It would be interesting to make it work without that sync lock though, so that multiple processes could be syncing dbox at the same time. But there probably isn't much point. If the sync is locked, there's no real requirement to do the syncing at all then, it's just left to be done later. If multiple processes were syncing at the same time, the only problem would come from flag updates. Either the files would have to be locked for flag updates (with waiting locks, bad bad), or it would need to be able to handle the situation when a flag was written just when another process expunged messages from the file and truncated it. That could be done by checking (one way or another) after the flag write if a truncation had happened, and if so do the truncation again. Preventing out of sync disconnects ================================== Reading messages from dbox files requires no locking, so it's possible that while one session is reading a message another session goes and expunges the message by truncating the file. The only way to handle this situation is to disconnect the client. Also even if the message wasn't in the middle of being read, this kind of a out-of-sync could happen if a session hasn't synced itself yet (no NOOP/IDLE/etc. for a while) and tries to begin reading an expunged message. These could be avoided if the expunging process knew that there are other processes that still know about the message, so it could just mark the message as expunged instead of actually doing it. I think this could be done with yet another file that tracks what messages are expunged. The file would contain "dovecot.index.log file sequence + offset" records. Whenever message(s) are expunged, a new seq +offset is written containing the position in the log file for that transaction. All the processes accessing the mailbox would then read lock the file from eof to infinity. The lock is updated whenever mailbox is synced (and being careful not to have race conditions there). So syncing process would then try if it can write lock the file from "last real expunge" log position to end of file. If not, then using some binary search find the position how far it can be locked. If it managed to update the write lock position at least some, the messages up to that far in the transaction log can be expunged safely. One problem with this is that the file needs to be rotated once in a while so that it won't grow infinitely. This can be done only if the write lock can include the whole file (including infinity). And that can be done only if there's a single process having the mailbox open, which may never happen with shared mailboxes. I think I'll leave this feature to be implemented later. It's extra overhead that's probably rarely useful. Single instance attachments =========================== I'll change the dbox messages to have variable sized headers. The header could then contain information such as "at offset 5000 insert 11241242 bytes from file AB123427852". Fast copying ============ Would be nice if copying a message from one mailbox to another wouldn't require actually reading+writing the whole message contents. But I can't really figure out how to implement this without requiring that there is only a single dbox storage which contains the mails for all the mailboxes, and the mailboxes themselves are just Dovecot's index files containing pointers to the dbox storage. The problem with having everything in one storage is that if the index files are broken, the messages can't be placed into correct mailboxes anymore. Although one possibility would be treat mailboxes a bit similarly than keywords. So that when a message is copied to another mailbox, the message in dbox file is updated to contain information that it exists in such and such mailboxes. Hmm. Perhaps that would be good enough, yes.

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