January 2016 - dovecot

sieve and authentication
by Brendan Kearney 20 Jan '16

20 Jan '16

when i telnet to the sieve instance running with dovecot, i see that SASL is supported, but i cannot get thunderbird to connect to the sieve instance. it seems that i am not providing the right auth methods for sieve to work. "IMPLEMENTATION" "Dovecot Pigeonhole" "SIEVE" "fileinto reject envelope encoded-character vacation subaddress comparator-i;ascii-numeric relational regex imap4flags copy include variables body enotify environment mailbox date index ihave duplicate" "NOTIFY" "mailto" "SASL" "" "STARTTLS" "VERSION" "1.0" OK "Dovecot ready." i am setup with gssapi and pain auth mechanisms and want to leverage Kerberos / SASL for authentication. what do i need to enable (and where) to get sieve working in a MUA? i tried adding the digest-md5 mechanism to the auth_mechanisms directive, but that does not work with Kerberos (or maybe my implementation of Kerberos in my environment). any ideas where i should be looking? thanks brendan

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remote | local blocks in protocol settings
by Nikolaos Milas 20 Jan '16

20 Jan '16

Hello, Where can I find detailed documentation on how "remote" & "local" blocks are used in protocol configuration to provide specific settings for particular IPs/Names? I've been searching around (wiki2, Google) but I found very few things. I also checked in the conf.d directory of the installation and couldn't find anything. One useful thread was here: http://www.dovecot.org/list/dovecot/2010-June/050069.html where we can read about the "filter" hierarchy: protocol name { remote <ip|name> { local <ip|name> { but I would really appreciate reading more complete documentation (and, hopefully, examples). Thanks, Nick

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Re: remote | local blocks in protocol settings
by Joseph Tam 19 Jan '16

19 Jan '16

Nikolaos Milas <nmilas(a)noa.gr> wrote: >> ... >> Pragmatically, I set it high enough so that it meets the need of most >> clients, then deal with problems on a case by case basis >> ... > > Thank you very much Joseph for your quite useful advice and experience. > Are you monitoring using "doveadm who"? No, I occasionally look at log entries for "Maximum number of connections from user+IP exceeded" errors. I may look at the output of "doveadm who" if I want to see a breakdown of how many clients a user is using, or just getting an overall view of how my users are spread out. >>> 4. How can we set a different value to this directive for webmail >>> connections (coming from 127.0.0.1, ::1)? >> >> I don't know if there is another method, but at the very least, you >> can start another dovecot instance with another config file that does >> specific things for 127.0.0.1. > > I tried using a remote block for webmail, but without success yet. If you can get that working, that would be the better method. Running 2 different instances with 2 different config files might come in handy for cases where you have very different policies between localhost/remote networks. Joseph Tam <jtam.home(a)gmail.com>

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Re: Increasing mail_max_userip_connections and sys resources
by Joseph Tam 19 Jan '16

19 Jan '16

> In our low-traffic server we have always kept the default value for IMAP > mail_max_userip_connections (10). > > The server has been working fine! (Thank you Timo for this!) > > However, recently we have been having: > > Maximum number of connections from user+IP exceeded > > errors both for IMAP and webmail users. > > Thus, we have now changed the value to 100. > > The questions: > > 1.Might this lead to overloading the server? > 2. Could another dovecot setting prevent the above setting from being > applied (e.g. due to connections exhaustion), i.e. should we also change > other setting(s)? > 3. What should we take into account when deciding the value for > mail_max_userip_connections? It depends on how many users you have, the number of simultaneous clients they use, and the #connections each client opens. Potentially, you could exhaust connection limits -- they usually don't max out memory or CPU or disk since most of the connections are idle. (There is a new IDLE hibernate feature that might help to minimize memory use by idle imap worker processes.) I haven't found a value that gets rid of users running into connection limits. If I set it to n, the next day someone will choke on n+1. This is a snapshot connections (count : #connections) which shows the typical decay: 25 1 14 2 14 3 7 4 9 5 1 6 2 7 1 8 1 10 Occasionally, some user's connection demand will spike and exceed the limit because - they started yat another client - they started global operation like searching - they're using a network that support roaming IP (I've tracked some users across the city on their bus ride.) Pragmatically, I set it high enough so that it meets the need of most clients, then deal with problems on a case by case basis (e.g. get them to lower their mail client's idle connection setting, or asking them to reduce the number of active clients by logging out). It also prevents what this setting was designed for: connection starvation by busy/buggy clients. Usually, hitting the limit doesn't produce problems as mail clients are smart enough to close idle connections or reuse them. If you only got a dozen users, setting it to 100 is feasible. If you got 1000 users, probably not. > 4. How can we set a different value to this directive for webmail > connections (coming from 127.0.0.1, ::1)? I don't know if there is another method, but at the very least, you can start another dovecot instance with another config file that does specific things for 127.0.0.1. Joseph Tam <jtam.home(a)gmail.com>

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Re: [BUG] 2.2.21 Panic: file imap-client.c: line 841 (client_check_command_hangs): assertion failed: (!have_wait_unfinished || unfinished_count > 0)
by Timo Sirainen 19 Jan '16

19 Jan '16

> On 04 Jan 2016, at 09:58, Florian Pritz <bluewind(a)xinu.at> wrote: > > On 04.01.2016 15:49, Timo Sirainen wrote: >> What about: >> >>>> #5 0x000000000041dde6 in client_check_command_hangs (client=0x2363450) at imap-client.c:841 >>>> cmd = 0x0 >>>> unfinished_count = 0 >>>> have_wait_unfinished = true >>>> __FUNCTION__ = "client_check_command_hangs" >> >> Either the new code that's detecting hanging-bugs is somehow broken or it's actually preventing a hang by crashing instead, in which case the bug is elsewhere.. > > Output below. > > Sending a private mail because I don't know what that session ID in the > output can be used for. The session ID is harmless. Anyway, I'm having trouble figuring out how the crash could happen or how to reproduce it. According to the backtrace it seems like the client is running IDLE and then it sends "DONE\r\nNOOP\r\n" in same IP packet. But when doing that, I don't see a crash. Although during testing I did find several other bugs. Could you try patching and seeing if you still get the same crash after them? Or have you seen the crash after the initial few times? https://github.com/dovecot/core/commit/1ddf959a750f3860feff4ab3f0e908f32740… https://github.com/dovecot/core/commit/c8e9fa2ffa2566e75f0500808b1bc9bf5d9d… https://github.com/dovecot/core/commit/15307c2c91854e766bd9fb095d611a29b3f7… https://github.com/dovecot/core/commit/c7801f830c7d2e7d340065cdd5a5c795b172…

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Temporary Lookup Failure
by Brad 18 Jan '16

18 Jan '16

Hi All, Have a CentOS 7, dovecot and postfix setup. Can get mail via 995 SSL/TLS Can send mail to virtual users and auto creation works using /etc/dovecot/passwd file via mail command. Using the dovecot lmtp and can login via 465 but the user lookup fails via postfix. in postfix main.cf have virtual_transport = lmtp:unix:private/dovecot-lmtp in dovecot.log I am seeing no errors in dovecot-info.log no errors either in maillog I am seeing: postfix/smtps/smtpd warning hash:/etc/postfix/virtual is unavailable open database /etc/postfix/virtual.db No such file. Note: I did go through creating the virtual.db and associated files but figured that it cant be correct as I want lmtp to handle it and it didn't work anyways, so I removed it. NOQUEUE reject RCPT from unknown[x.x.x.x] 451 4.3.0 <user@domain> Temporary lookup failure from=<user@domain> to=<user@domain> proto=ESMTP helo=<localhost.localdomain> -- obfuscated Tried every article I could find on the Internet to resolve this with out much luck. Any pointers would be greatly appreciated or if you need specific config details just let me know. Thanks, Brad

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Dovecot doesn't listen on port 143, 993 in SSL
by 남설 18 Jan '16

18 Jan '16

Dear Dovecot Team First of all, I always appreciated your contribution & effort. Dovecot is very good tool for me for a while since my 2 years Linux start. But, 3 days ago, I upgraded my ubuntu 15.04 to 15.10 Then, I realized that my dovecot mail sever didn't work. So I simply terminated all the packages and reinstall it. It means I can't remeber what my previous setting was in my memory. So, dovecot in run is ver 2.2.18 now. Dovecot -n shows below and there is no "SSL" option. then all the port 143, 993 opens(It's not accesible somehow from clients but it's next matter) ----------------------No SSL version------------------------ auth_mechanisms = plain login mail_location = maildir:~/Maildir namespace inbox { inbox = yes location = mailbox Drafts { special_use = \Drafts } mailbox Junk { special_use = \Junk } mailbox Sent { special_use = \Sent } mailbox "Sent Messages" { special_use = \Sent } mailbox Trash { special_use = \Trash } prefix = } passdb { driver = pam } protocols = " imap" service auth { unix_listener /var/spool/postfix/private/auth { group = postfix mode = 0666 user = postfix } } userdb { driver = passwd } ----------------------------------------------------------- But, If I turn on SSL option with encrypt key and certicate, all port 143, 993 just disappeared. I treaded this issue in ubuntu ASK but still no proper answer so far http://askubuntu.com/questions/722072/dovecot-doesnt-listen-on-993imaps --------------------------SSL option version---------------- auth_mechanisms = plain login mail_location = maildir:~/Maildir namespace inbox { inbox = yes location = mailbox Drafts { special_use = \Drafts } mailbox Junk { special_use = \Junk } mailbox Sent { special_use = \Sent } mailbox "Sent Messages" { special_use = \Sent } mailbox Trash { special_use = \Trash } prefix = } passdb { driver = pam } protocols = " imap" service auth { unix_listener /var/spool/postfix/private/auth { group = postfix mode = 0666 user = postfix } } *ssl_cert = </etc/dovecot/dovecot.csr>** **ssl_key = </etc/dovecot/private/dovecot.key>* userdb { driver = passwd } -------------------------------------------------------------- Looing forward your reply Thanks in advance

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mmap failed
by ＠lbutlr 18 Jan '16

18 Jan '16

Error: mmap() failed with file /home/user/Maildir/.Archive/dovecot.index.cache: Cannot allocate memory I have default_vsz_limit = 512 M in my conf file. (This error only occurs with a single user’s .Archive index, but that user has over 400,000 files int eh Archive mailbox) -- Let him who desires peace, prepare for war.

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doveconf syntax question
by A. Schulze 18 Jan '16

18 Jan '16

Hello, I have one sieve extension enabled: /etc/dovecot/conf.d/20-sieve.conf: plugin { sieve_extensions = +vacation-seconds } now (months later) we want to enable an other extension. no big deal: /etc/dovecot/local.conf: plugin { sieve_extensions = +editheaders ... } This was wrong. We ASSUMED the plus would add the extension to the list. But at the end only +editheaders was activ. What's the right way to /add/ sieve_extensions from different config files? our guess "sieve_extensions = $sieve_extensions +editheaders" do not work: doveconf -a | grep sieve_extensions doveconf: Fatal: Error in configuration file /etc/dovecot/local.conf line 22: Unknown variable: $sieve_extensions doveconf: Error: managesieve-login: dump-capability process returned 89 doveconf: Fatal: Error in configuration file /etc/dovecot/local.conf line 22: Unknown variable: $sieve_extensions Andreas

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Running without anvil?
by Dave Abrahams 18 Jan '16

18 Jan '16

Hi, I'm using dovecot as a local mail store on my laptop using preauth tunneling. It turns out I almost don't even need to start dovecot at all; the only reason it needs to be running is so that FTS indexing can be invoked. And because I don't want it to run any services, I can run it as an unprivileged user, so long as I turn them all off: # We don't want to serve any protocols, so we don't bind to any ports. # We can run everything as me. protocols = default_login_user = dave default_internal_user = dave The only thing is, I keep getting these in var/log/mail.log: anvil: Fatal: chroot(/Users/dave/brew/var/run/dovecot/empty) failed: Operation not permitted master: Error: service(anvil): command startup failed, throttling for 60 secs auth: Error: read(anvil-auth-penalty) failed: EOF Any suggestions? TIA, Dave

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