March 2020 - dovecot - dovecot.org

Understanding doveadm rebuild
by Patrick Ben Koetter 26 Mar '20

26 Mar '20

Greetings, I'm trying to understand if the doveadm rebuild command is suited to fix a problem we have on a customers platform. The customer uses sdbox in combination with SIS and for $REASONS dovecot cannot find the attachements anymore. They are there, but the references to them in the messages seem to be wrong. Is that what the rebuild subcommand has been made for? Will it e.g. scan the messages for attachment references and try to find them in the SIS storage location and then fix the references in messages? TIA, p@rick -- [*] sys4 AG https://sys4.de, +49 (89) 30 90 46 64 Schleißheimer Straße 26/MG,80333 München Sitz der Gesellschaft: München, Amtsgericht München: HRB 199263 Vorstand: Patrick Ben Koetter, Marc Schiffbauer, Wolfgang Stief Aufsichtsratsvorsitzender: Florian Kirstein

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At rest encryption (with protected crypto keys)
by Kees de Jong 25 Mar '20

25 Mar '20

Hi, As stated on the Dovecot documentation, at rest encryption is possible [1]. However, these keys are present on the system itself and are unprotected. Therefore, if a system is compromised, the attacker has access to the encrypted mail and the keys. There is no security benefit in that situation, except for hoping that the attacker doesn't understand that this is happening and how. Nextcloud does this a bit better. A key is used to encrypt user data as well [2]. However, that key is protected with the user's password. When the user logs in and requests data, the user's password unlocks the key and data can be read and written safely. This also takes into account password changes. Files don't need to be encrypted again, the encryption key is simply re-encrypted with the new user's password. How does the Dovecot community see this? Is at rest encryption needed in times of increased security and privacy problems? I think it is a must, just like 2FA, but that's a different story. I think the current possibility of at rest encryption is not well applied enough. Is this something that's on the agenda to improve? Or am I missing something? Is there a better way of doing this? [1] https://doc.dovecot.org/configuration_manual/mail_crypt_plugin/#mail-crypt-… [2] https://nextcloud.com/encryption/

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dovecot-2.2.36-4 and antispam
by Maciej Milaszewski 24 Mar '20

24 Mar '20

Hi I use dovecot-2.2.36.4 on Debian 8.11 and plugin dovecot-antispam from http://johannes.sipsolutions.net/Projects/dovecot-antispam All works fine but in roundcube i get two folder: Spam (real: Junk) and SPAM in sieve i have: require ["fileinto","imap4flags"]; # rule:[SPAM Box] if header :contains "X-Spam-Flag" "YES" { setflag "\\Seen"; fileinto "SPAM"; # ---> because dovecot-antispam need folder SPAM to teach spam or ham stop; } problem probably fixed when I change fileinto "SPAM"; to fileinto "Junk"; But plugin "dovecot-antispam" probably not working ... Maybe I think wrongly Can you recommend any other plugin that will work properly and teach spam with Junk for dovecot2.2.36-4 in dovecot: 15-mailboxes.conf: ....... mailbox Drafts { special_use = \Drafts } mailbox Junk { special_use = \Junk } mailbox SPAM { special_use = \Junk } mailbox Trash { special_use = \Trash } .... 90-plugin.conf: ..... antispam_backend = MAILTRAIN #antispam_mail_sendmail_args = --for;%u antispam_mail_spam = --spam antispam_mail_notspam = --ham antispam_mail_sendmail = /usr/local/bin/spam-learn.sh antispam_pipe_tmpdir = /tmp antispam_spam_pattern_ignorecase = spam;inbox.spam;Unwanted antispam_trash_pattern_ignorecase = trash;Deleted *;Junk*;wiadomo&AVs-ci-&AVs-mieci;kosz antispam_debug_target = syslog antispam_verbose_debug = 1 script to learn cat /usr/local/bin/spam-learn.sh #!/bin/sh date >> /tmp/spam.txt echo $@ >> /tmp/spam.txt if [ "x$1" = "x--spam" ]; then /usr/bin/pyzor report >> /tmp/spam.txt 2>&1 fi if [ "x$1" = "x--ham" ]; then /usr/bin/pyzor whitelist >> /tmp/ham.txt 2>&1 fi -- Maciej Miłaszewski Starszy Administrator Systemowy IQ PL Sp. z o.o. Biuro Obsługi Klienta: e-mail: bok(a)iq.pl tel.: +48 58 326 09 90 - 94 fax: +48 58 326 09 99 Dział pomocy: https://www.iq.pl/pomoc Informacja dotycząca przetwarzania danych osobowych: https://www.iq.pl/kontakt IQ PL Sp. z o.o. z siedzibą w Gdańsku (80-298), ul. Geodetów 16, KRS 0000007725, Sąd rejestrowy: Sąd Rejonowy w Gdańsku VII Wydział KRS, kapitał zakładowy: 140.000 PLN, NIP 5832736211, REGON 192478853

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imapc quota support
by Сергей Петренко 24 Mar '20

24 Mar '20

Hi, I use Dovecot 2.3.9.2 as IMAP proxy for other mail server and configure it with imapc_host/imapc_port/imapc_user options. All works fine exclude quota information. Although my IMAP server supported quota Dovecot does not relay it to users. As I read in docs/MailboxFormat.imapc.txt in Dovecot v2.2.30+ there is a way to relay quota data to end users: Quota ----- Using the "imapc" quota backend allows asking for the quota from remote IMAP server (v2.2.30+). By default it uses GETQUOTAROOT INBOX for getting the quota. There are also two parameters that can be used to control how the quota is looked up: * box=<mailbox>: Use GETQUOTAROOT <mailbox> * root=<name>: Use GETQUOTA <name> For example: ---%<------------------------------------------------------------------------- plugin { quota = imapc:root=User Quota } ---%<------------------------------------------------------------------------- The above example is not clear. Please advise how to configure Dovecot in IMAP proxy mode with quota support.

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Question on pop3
by ratatouille 23 Mar '20

23 Mar '20

Hello! Email is stored as plain textfile in /var/mail/andreas. I assume this is mbox-format. I get the following in the log telneting to localhost: 2020-03-22 20:21:10 imap(andreas(a)dualbit.de): Error: chdir(/var/spool/mail/andreas) failed: Not a directory 2020-03-22 20:21:10 imap(andreas(a)dualbit.de): Error: Namespace '': Mail storage autodetection failed with home=/var/spool/mail/andreas 2020-03-22 20:21:10 imap(andreas(a)dualbit.de): Info: Namespace '': Mail storage autodetection failed with home=/var/spool/mail/andreas in=0 out=372 In case in the passwd-file I specify userdb_mail=mbox:/var/mail/andreas:INBOX=/var/mail/%n I see: 2020-03-22 20:31:00 imap(andreas(a)dualbit.de): Error: chdir(/var/spool/mail/andreas) failed: Not a directory 2020-03-22 20:31:00 imap(andreas(a)dualbit.de): Error: Namespace '': mbox: mbox root directory can't be a file: /var/mail/andreas (http://wiki2.dovecot.org/MailLocation/Mbox) How can I make this work? Regards Andreas

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Problem with mail_uid
by ratatouille 23 Mar '20

23 Mar '20

Hello! I have problems fetching mail for a system user. In use is a passwd-file. If I set (for virtual users) mail_uid = vmail mail_gid = vmail in 10-mail.conf, I get permission denied. 2020-03-23 18:39:23 imap(andreas(a)dualbit.de): Error: chdir(/home/andreas/Maildir/) failed: Permission denied (euid=5000(vmail) egid=5000(vmail) missing +x perm: /home/andreas/Maildir, dir owned by 5006:5006 mode=0700) The mailbox has permissions drwx------. 9 andreas susers If I don't set mail_uid I get an error because of missing mail_uid. I can only access the users mailbox if I set mail_uid = 5006 in 10-mail.conf On another system I don't haver this problem. I made diffs, read alot of stuff and can't find a solution. What is the way to go, please? I would like to know why this does not work. Below my doveconf -n # 2.2.36 (1f10bfa63): /etc/dovecot/dovecot.conf # Pigeonhole version 0.4.24 (124e06aa) # OS: Linux 3.10.0-1062.9.1.el7.x86_64 x86_64 CentOS Linux release 7.7.1908 (Core) # Hostname: dualbit1.dualbit.de auth_debug = yes auth_debug_passwords = yes auth_mechanisms = plain cram-md5 auth_verbose = yes auth_verbose_passwords = yes debug_log_path = /var/log/dovecot-debug disable_plaintext_auth = no first_valid_uid = 1000 listen = *,[::] log_path = /var/log/dovecot log_timestamp = "%Y-%m-%d %H:%M:%S " mail_gid = vmail mail_home = /home/%n/Maildir mail_location = maildir:~/ mail_plugins = " quota" mail_privileged_group = vmail mail_uid = 5006 managesieve_notify_capability = mailto managesieve_sieve_capability = fileinto reject envelope encoded-character vacation subaddress comparator-i;ascii-numeric relational regex imap4fl ags copy include variables body enotify environment mailbox date index ihave duplicate mime foreverypart extracttext mbox_write_locks = fcntl 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 = separator = / } passdb { args = /etc/dovecot-sql.conf driver = sql } passdb { args = scheme=CRYPT username_format=%u /etc/dovecot/users driver = passwd-file } plugin { quota = dict:user::file:/var/vmail/%d/%n/.quotausage sieve = file:~/sieve;active=~/.dovecot.sieve } protocols = imap pop3 service auth { unix_listener /var/spool/postfix/private/auth { group = postfix mode = 0660 user = postfix } unix_listener auth-userdb { group = vmail mode = 0666 user = vmail } user = root } service imap-login { client_limit = 1000 process_limit = 500 } service lmtp { unix_listener /var/spool/postfix/private/dovecot-lmtp { group = postfix mode = 0600 user = postfix } } ssl = required ssl_cert = </etc/pki/dovecot/certs/dovecot.pem ssl_key = # hidden, use -P to show it ssl_protocols = !SSLv3 userdb { driver = prefetch } userdb { args = /etc/dovecot-sql.conf driver = sql } userdb { args = username_format=%u /etc/dovecot/users driver = passwd-file } protocol imap { mail_plugins = quota imap_quota } protocol pop3 { mail_plugins = quota pop3_uidl_format = %08Xu%08Xv } protocol lda { mail_plugins = sieve quota postmaster_address = root@localhost } protocol lmtp { mail_plugins = quota sieve } Any help appreciated. Andreas

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imapc master login for shared mailboxes
by Mark Zealey 21 Mar '20

21 Mar '20

Hi there, I'm trying to set up shared mailboxes such that any access to the shared namespace like INBOX/shared/<sub-email-address> will take <current-user> and use imapc to log in with <sub-email-address>*<current-user> (ie the current user is the master account for imapc). I've set up like https://wiki2.dovecot.org/SharedMailboxes/ClusterSetup on centos8 latest dovecot build (a late 2.2 series version I believe. However I'm running in to a couple of issues: 1) setting imapc_master_user = %u has %u as <sub-email-address> rather than <current-user>. I can't find any sort of variable substitution that will allow me to access the details of <current-user>. From looking at the logs it seems to do a userdb lookup for<sub-email-address> to check it exists but then the substitutions appear to be using these rather than the current user's details 2) In a similar vein, I believe imapc_password = %w (ie trying to just get current user logging in with the password that was specified when they initially logged in, but as a master user) is also not substituting correctly and is just a blank string Is there any way around this so I don't have to worry about trying to do sharing based on the filesystem and the same process but rather just allow the main user to log in to any other account (in this case domain owner logging in to any accounts under their domain) ? Thanks Mark

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systemuser login
by ratatouille 20 Mar '20

20 Mar '20

Hello! I have one systemuser on my testsystem running CentOS. All other users live in a mysql- database. I created a /etc/dovecot/users file and use auth-passwdfile.conf.ext. andreas@dualbit.de:{CRAM-MD5}334bb91aad4fb976870535bbbd9f07db512fce13bc8f7b58f9dedca404a421aa:5006:5006::/var/spool/mail/andreas::userdb_mail=mbo x:/var/mail/andreas:INBOX=/var/mail/%u When I try to login via telnet I see in the logifle: 2020-03-20 14:40:01 auth: Debug: prefetch(andreas@dualbit.de,::1,<+9T4a0mhKO0AAAAAAAAAAAAAAAAAAAAB>): success 2020-03-20 14:40:01 auth: Debug: master userdb out: USER 734789633 andreas(a)dualbit.de mail=mbox:/var/mail/andreas:INBOX=/var/ma il/andreas(a)dualbit.de auth_token=dc1f852724345081ff3a18958f05fc61b2544ab4 The domainpart is added to the username when I use %u. I assume this is why the login fails. How do I correct this, please? Kind regards Andreas

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Director with dovecot 2.3 and Panic/Fatal error
by Alessio Cecchi 19 Mar '20

19 Mar '20

Hi, after the upgrade to Dovecot 2.3 for our director ring we found some times in the log errors like this: Mar 18 14:22:51 Panic: imap-login: file iostream-openssl.c: line 599 (openssl_iostream_handle_error): assertion failed: (errno != 0) Mar 18 14:22:51 Fatal: imap-login: master: service(imap-login): child 1726 killed with signal 6 (core dumps disabled - https://dovecot.org/bugreport.html#coredumps) Backend is still Dovecot 2.2.36 and Director is 2.3.10. I hope it can be fixed. Thanks -- Alessio Cecchi Postmaster @ http://www.qboxmail.it https://www.linkedin.com/in/alessice

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.dovecot.sieve.log/tmp failed: Not a directory
by mabi 19 Mar '20

19 Mar '20

Hello I am running Dovecot 2.3.9 for IMAP access with RainLoop webmail and have noticed for an account where I have some filters setup that I get the following error messages in the dovecot log file: Mar 17 19:02:50 mbox dovecot: imap(mail(a)domain.tld)<10511><ubAzvhCh1N2yxeu/>: Error: stat(/var/vmail/domain.tld/mail/.dovecot.sieve/tmp) failed: Not a directory Mar 17 19:02:50 mbox dovecot: imap(mail(a)domain.tld)<10511><ubAzvhCh1N2yxeu/>: Error: stat(/var/vmail/domain.tld/mail/.dovecot.sieve.log/tmp) failed: Not a directory This happens when I access the Dovecot mailbox server using an iphone. Also on the iphone I see these "mail" folders but they are not really mail folders... With Thunderbird as mail client it looks all good and I don't get this error. Is this normal? if not, how can I prevent this issue? Regards, Mabi

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