April 2020 - dovecot - dovecot.org

Recommendations on intrusion prevention/detection?
by Johannes Rohr 23 Apr '20

23 Apr '20

Dear all, what are the key strategies for intrusion prevention and detection with dovecot, apart from installing fail2ban? It is a pity that the IMAP protocol does not support 2 factor authentication, which seems to stop 90% of intrusion attempts in their tracks. Without it, if someone has obtained your password and reads your mail without modifying it, you will hardly ever notice. Is there a reasonable way of detecting and preventing logins from unusual IP ranges? Or are there other strategies you would recommend? Cheers, Johannes

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Dovecot and thunderbird authentication issue?
by David Mehler 23 Apr '20

23 Apr '20

Hello, I'm using Dovecot 2.2, Postfix 3.5, and am atempting to get the latest version of Thunderbird to work. I tried account autoconfig which did not work, so I had to manually enter information and correct other information. On my server dovecot supports plane and login authentication methods but only over starttls i've got a letsencrypt certificate. My thunderbird configuration looks good, right hosts for incoming and outgoing mail, right ports, 143 starttls, and 587 smtp submission, and thunderbird has the authentication method set for normal password. This I interpreted to mean thunderbird is going to starttls then send the username and password. Thunderbird is giving me this error: imap server does not support the selected authentication method I realize this is vague, any suggestions? Thanks. Dave.

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sieve question
by mj 23 Apr '20

23 Apr '20

Hi, We are trying to auto-reply to emails that still use one of our old domains. To do this, I have setup a catch-all mailbox for anything sent to that old domain using postfix virtual: @old.domain.com catch-all(a)new.domain.com Then I defined a sieve script for catch-all(a)new.domain.com, like: > require ["vacation"]; > if allof ( not exists ["list-help", "list-unsubscribe", "list-subscribe", "list-owner", "list-post", "list-archive", "list-id", "Mailing-List"] ) > > { vacation text: > This message is sent automatically, and your message has NOT been read nor forwarded. > > Please update your addressbooks! > > All the best! :-) > . > ; > } However, sieve never sends any auto-reply, because it logs: > discarding vacation response for implicitly delivered message; no > known (envelope) recipient address found in message headers > (recipient=<catch-all(a)new.domain.com>, and no additional `:addresses' > are specified) I have googled this, but adding :addresses in this case will not work, as we are trying to answer (basically) emails sent to any email addresses sent to that domain, and thus I cannot define specific :addresses Can anyone suggest what to do here? Thanks and stay healthy! MJ

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Still interested in SMTPUTF8 support
by David Bürgin 22 Apr '20

22 Apr '20

I haven’t seen this term on the mailing list for a while. I don’t know if you’re tracking this somewhere, in any case I’m curious if you are still planning to add support for SMTPUTF8. Cheers,

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Dovecot 2.3.10 fails to start due to missing dependency
by Jacob Shea 21 Apr '20

21 Apr '20

Greetings, I installed Dovecot 2.3.10 on my Centos 7.7.1908 server, however it fails startup. This is a fresh/default install, meaning all the configs are default, downloaded from the dovecot.repo. Here is my PasteBin: https://pastebin.com/376UQFLs ### Error Log, copied from Journalctl print out ### Apr 20 21:10:01 server101 systemd[1]: Started Session 955 of user root. Apr 20 21:10:01 server101 CROND[8057]: (root) CMD (/usr/lib64/sa/sa1 1 1) Apr 20 21:10:18 server101 polkitd[1293]: Registered Authentication Agent for unix-process:8065:44125203 (system bus name :1.2058 [/usr/bin/pkttyagent --notify-fd 5 --fallback], object path /org/freedesktop/Polic Apr 20 21:10:18 server101 systemd[1]: Starting One-time Dovecot init service... Apr 20 21:10:18 server101 systemd[1]: dovecot-init.service: main process exited, code=exited, status=2/INVALIDARGUMENT Apr 20 21:10:18 server101 systemd[1]: Failed to start One-time Dovecot init service. Apr 20 21:10:18 server101 systemd[1]: Dependency failed for Dovecot IMAP/POP3 email server. Apr 20 21:10:18 server101 systemd[1]: Job dovecot.service/start failed with result 'dependency'. Apr 20 21:10:18 server101 systemd[1]: Unit dovecot-init.service entered failed state. Apr 20 21:10:18 server101 systemd[1]: dovecot-init.service failed. Apr 20 21:10:18 server101 polkitd[1293]: Unregistered Authentication Agent for unix-process:8065:44125203 (system bus name :1.2058, object path /org/freedesktop/PolicyKit1/AuthenticationAgent, locale en_US.UTF-8 lines 6106-6158/6158 (END) ### Linux Server Version ### [root@server101 log]# cat /etc/centos-release CentOS Linux release 7.7.1908 (Core) ### Dovecot Version ### Installed Packages Name : dovecot Arch : x86_64 Epoch : 2 Version : 2.3.10 Release : 2 Size : 15 M Repo : installed From repo : dovecot-2.3-latest Summary : Secure imap and pop3 server URL : http://www.dovecot.org/ License : MIT and LGPLv2 Description : Dovecot is an IMAP server for Linux/UNIX-like systems, written with security : primarily in mind. It also contains a small POP3 server. It supports mail : in either of maildir or mbox formats. : : The SQL drivers and authentication plug-ins are in their subpackages. ---- Any help or suggestions are appreciated. Sincerely, Jacob S.

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Unicode in mail addresses
by Jasper Michalke 21 Apr '20

21 Apr '20

Dear Dovecot people, I have a question concering Unicode support: Does Dovecot support Unicode characters in both parts of the mail address? E.g. dфҿ@.tld Thank you for any reply, The one with the braid | Der mit dem Zopf

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Doc pointer request
by David Favor 18 Apr '20

18 Apr '20

At one point seems like I found a write up in the Dovecot docs about having Dovecot directly listen on port 25 using Opportunistic TLS along with port 587 authentication, so only Dovecot was required to handle incoming email. Said another way, no requirement for Sendmail, or Postfix or EXIM. Just straight up Dovecot. If I'm remembering correctly, someone point me to the correct docs for this setup. Thanks!

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setup sdbox per user with userdb
by Maciek Jackowski 18 Apr '20

18 Apr '20

Hi welcome I want to set some virtual users with sdbox mail_location so I return in password_query and user_query extra field mail which contains sdbox:/var/mail/example.com/user:INDEX=/var/mail_indexes/example.com/user:A… and then when i send email to user(a)example.com I see all sdbox dirs created but when i login with thunderbird IMAP - Maildir structure is always created with an empty INBOX I tried to override namespace inbox with mail AS "namespace/inbox/location" with content sdbox:/var/mail/example.com/user:INDEX=/var/mail_indexes/example.com/user:A… but nothin change what am I doing wrong? regards

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Problems with compressed mail_attachment_dir
by Claudio Cuqui 17 Apr '20

17 Apr '20

Hi there ! I´m using dovecot 2.3.10 (manually compiled on Centos 8 x86_64 - fully updated), XFS filesystem, with mdbox and a separated compressed attachment directory: mail_attachment_fs = sis compress:lz4:6:posix mail_attachment_hash = %{sha256} mail_attachment_dir = /ATTACHMENTS I'm using dovecot LDA (for mail delivery). Everything works fine with the delivery and compression. The first test, I send one tar file with 7Mb. It was correctly compressed (2791959) and stored in mail_attachment_dir. But when I tried to access it via IMAP ( thunderbird/evolution) I got this message on dovecot logs: Error: Mailbox INBOX: UID=1: read(attachments-connector(zlib(/mailboxes/domain/h1/h2/test/mdbox/storage/m.1))) failed: read(/ATTACHMENTS/19/53/19536d7b190e5ba68337625a29e7b8a6129a2dfb5935eafa424ba4da2a878532-2e9c960b7dd2985e245e0000f484007a[base64:19 b/l]) failed: Stream is smaller than expected (2791959 < 7981633) (FETCH BODY[]) The 7981633 is the original attachment size. 2791959 is the compressed size (on attachment directory). I also see 2791959 in mail message size field (instead of 7981633 that is the original size BEFORE compression) in Thunderbird. In Evolution was not even possible to open the message. Thunderbird allow me even download the attachment, but the downloaded file is corrupted. Looks like dovecot is showing the properties of the compressed attachment instead of the proprerties of the original attachment (before compression). I'm also using imap_zlib and zlib plugins: plugin { zlib_save_level = 6 # 1..9; default is 6 zlib_save = lz4 # or bz2, xz, lz4 or zstd } protocol imap { # Space separated list of plugins to load (default is global mail_plugins). mail_plugins = $mail_plugins imap_quota imap_zlib } # Space separated list of plugins to load for all services. Plugins specific to # IMAP, LDA, etc. are added to this list in their own .conf files. mail_plugins = quota fts fts_xapian mailbox_alias zlib This happens with every message that exceed mail_attachment_min_size (in my case, 32k) and is stored at mail_attachment_dir = /ATTACHMENTS When I comment: mail_attachment_dir = /ATTACHMENTS, everything works fine (compression included) with imap viewing on Thunderbird/Evolution. Please, let me know if you need further information or have any suggestions about this issue. TIA, Claudio

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Headsup on feature removal
by Aki Tuomi 17 Apr '20

17 Apr '20

Hi! Dovecot is now a nearly 20 year old product, and during that time it has accumulated many different features and plugins in its core repository. We are starting to gradually remove some of these parts, which are unused, untested or deprecated. We will provide advance notification before removing anything. To start, the following features are likely to be removed in next few releases of Dovecot. - Authentication drivers: vpopmail, checkpassword, bsdauth, shadow, sia - Password schemes: HMAC-MD5, RPA, SKEY, PLAIN-MD4, LANMAN, NTLM, SMD5 - Authentication mechanisms: ntlm, rpa, skey - Dict drivers: memcached, memcached-ascii (use redis instead) - postfix postmap support - autocreate & autosubscribe plugins (use built-in auto=create/subscribe setting instead) - expire plugin (use built-in autoexpunge setting) - fts-squat plugin - mailbox alias plugin - mail-filter plugin - snarf plugin - xz compression algorithm For the authentication drivers that are being removed, we suggest using Lua as a replacement. See https://doc.dovecot.org/configuration_manual/authentication/lua_based_authe… For information about converting between password schemes, see https://wiki2.dovecot.org/HowTo/ConvertPasswordSchemes If you are using any of these features, please start preparing for their removal in the near future. Features will begin to be dropped as of v2.3.11. Additionally, the mbox format will no longer receive new development. It will still be maintained, however its use beyond migrations and other limited use cases will be discouraged. Please contact us via the mailing list if you have any questions. Regards, Dovecot Team

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