May 2020 - dovecot - dovecot.org

Compress by zlib only selected Maildir folders
by filbar＠centrum.cz 12 May '20

12 May '20

Hello, is it possible to compress by zlib only selected folders? My e-mail accounts have archive folder and this folder contains old comunications with my customers and this I use very rare, so I want to compress them by zlib to save space. Is this possible? Thanks, Filip Bartmann

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Deleting messages from filesystem with sdbox mail format
by Gionatan Danti 11 May '20

11 May '20

Dear list, I recently had to delete some messages from an sdbox mailbox, for which I used the canonical "doveadm expunge" command without issues. However I got curious and, on a test mailbox, I deleted an unimportant message directly from the filesystem (rm u.650). After removing the file, the webmail continued to show it in the mail list - but no text was retrieved when I selected it. I supposed this was due to dovecot.index.cache and, indeed, deleting the cache got rid of the message in the webmail list. While I understand that it is not recommended (deleting and regenerating the index cache is an expensive operation), I wonder if removing a file from the filesystem, and regenerating the index cache file, is a safe operation when using an sdbox mailstore. Specifically, I would like to know if, after a manual filesystem deletion, the main index file (dovecot.index) is automatically updated by dovecot (reflecting the deletion) or if lingering references are kept in it. Thanks. -- Danti Gionatan Supporto Tecnico Assyoma S.r.l. - www.assyoma.it [1] email: g.danti(a)assyoma.it - info(a)assyoma.it GPG public key ID: FF5F32A8

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Re: [EXT] Support for MULTISEARCH
by Sami Ketola 11 May '20

11 May '20

> On 10. May 2020, at 11.22, Peter <pch(a)myzel.net> wrote: > > Am 10.05.20 um 09:54 schrieb Sami Ketola: >>> On 10. May 2020, at 1.51, Peter <pch(a)myzel.net> wrote: >>> Am 10.05.20 um 00:22 schrieb Daniel Miller: >>>> Thank you - I'm aware of the virtual folder option and do use it. My interest is for a Windows client, EM Client, which I otherwise really enjoy. Unfortunately, they've implemented server-side searching only via MULTISEARCH - for reasons passing my understanding. So I was hoping to hear Dovecot either already had support or there were plans to implement it. >>> >>> Virtual folder does not scale. Thank you for naming a client that does multisearch! >> Virtual folder scales just fine. What makes you think it does not? >> We have customers that have users with thousand folders and millions of emails and still virtual folder scales. > > Hello Sami, I was thinking, that the client then will be overwhelmed with a mailbox of such a size? > > Or does the folder start empty and only gets populated upon search with the resulting mails? virtual folder with contents of all actual folders is usually hidden from imap clients and is used only for searching. Sami

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Directory hashing
by lists＠mlserv.org 11 May '20

11 May '20

Hi, I struggle with directory hashing. I want something like this: /srv/mail/c/cf37a8dff5e360927ba10ab2 The final folder is simpel, as it is: %{sha256;truncate=96:user} But how do I get a first level from sha256? Unfortunately, the truncate option aligns only full 8bit and does not divide into low and high nibbles. How can I express this for sha256? in MD5 this would be %1Mu Many thanks in advance Christian -- Rößner-Network-Solutions Karl-Bröger-Str. 10, 36304 Alsfeld Fax: +49 6631 78823409, Mobil: +49 171 9905345 USt-IdNr.: DE225643613, https://roessner.website PGP fingerprint: 658D 1342 B762 F484 2DDF 1E88 38A5 4346 D727 94E5

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Unable to disable TLSv1.3 or fallback to TLSv1.2 when 1 cipher is disabled
by Steve Egbert 10 May '20

10 May '20

I have an operational need to disable TLSv1.3 due to inadequate support to exclude certain ciphers. Much to my dismay, the `ssl_protocols` had been renamed and re-functionalized into `ssl_min_protocol`. Now, there is no way to exclude a specific group of one or more TLS versions. For a new bug report, I think we need two new settings: * `ssl_tls13_ciphersuite` and * `ssl_tls10_cipher` settings introduced into Dovecot for better granularity. ALong with support for fallback to TLSv1.2 as outlined in https://bugzilla.mozilla.org/show_bug.cgi?id=1250568 I'm still being hammered with the following error with Thunderbird 76.0b3, Dovecot 2.3.4.1-5+deb10u1, Debian 11: May 8 11:15:47 ns1 dovecot: imap-login: Debug: SSL: where=0x10, ret=1: before SSL initialization May 8 11:15:47 ns1 dovecot: imap-login: Debug: SSL: where=0x2001, ret=1: before SSL initialization May 8 11:15:47 ns1 dovecot: imap-login: Debug: SSL: where=0x2002, ret=-1: before SSL initialization May 8 11:15:47 ns1 dovecot: imap-login: Debug: SSL: where=0x2001, ret=1: before SSL initialization May 8 11:15:47 ns1 dovecot: imap-login: Debug: SSL alert: where=0x4008, ret=582: fatal protocol version May 8 11:15:47 ns1 dovecot: imap-login: Debug: SSL: where=0x2002, ret=-1: error May 8 11:15:47 ns1 dovecot: imap-login: Debug: SSL error: SSL_accept() failed: error:14209102:SSL routines:tls_early_post_process_client_hello:unsupported protocol May 8 11:15:47 ns1 dovecot: imap-login: Disconnected (disconnected before auth was ready, waited 0 secs): user=<>, rip=XX.XX.XX.XX, lip=XX.XX.XX.XX, TLS handshaking: SSL_accept() failed: error:14209102:SSL routines:tls_early_post_process_client_hello:unsupported protocol, session=<GN/GeCSlYuhEhl2U> May 8 11:15:47 ns1 dovecot: imap-login: Debug: SSL error: SSL_accept() syscall failed: Invalid argument This occurred when specifying one TLSv1.3 cipher to be excluded in ssl_cipher via an exclamation mark. On a side note of IMAP client, Latest Mozilla Thunderbird had its pref setting security.tls.version.fallback-limit to 4 (TLSv1.3), of which I have adjusted it to 3 (TLSv1.2) and it .... works when Dovecot is set to TLSv1.2. (Details of Thunderbird security.tls.version.fallback-limit is given in http://kb.mozillazine.org/Security.tls.version.* ) Steve

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Marking all emails in "Trash" as opened, and also prohibiting email clients from creating new mails
by Sebastian Nielsen 10 May '20

10 May '20

Dovecot version: 2.3.7.2 (3c910f64b) (pkg shipped by: Ubuntu-Desktop 20.04) I want to accomplish 2 things in dovecot: 1: I want to force all mails inside Trash to have an "opened"/"read" flag and "Non-Recent" flag. Basically Status: RO This regardless how the flag appears, either by copying/moving the mail into trash, creating a new mail in trash, flagging email in Trash or whatever. Basically, no email in Trash should ever be able to have a recent or unread flag. I tried with a static mail filter and sieve filter to add \\seen to the email upon COPY (as mentioned here: https://dovecot.org/pipermail/dovecot/2017-November/110122.html ), but regardless how I do it, it doesn't work when Samsung Email client trashes an unread email, AND/OR also, it causes weird issues like duplicate email in the trash folder sometimes. Best would be some event filter that executes for every mail that somehow end up in Trash, that checks if \\seen is present, if not, then it will add it, on all emails in trash? But how I do to prevent the duplicate copy that appears sometimes? 2: I want to prohibit email clients from ever creating a new mail in Sent folder. If its possible to allow MOVE and/or COPY, it should be allowed, only new mail should be prohibited. (also note that external processes must be able to create new mail in Sent) HOWEVER - this prohibition must be silent - ergo the newly created email is simply discarded. No error message or error codes should be returned to IMAP client. (The reason I want this, is because I have configured my outgoing SMTP server to populate Sent, and some email clients doesn't have the option to "Don't store a copy of the email in Sent folder" resulting in duplicates) Best regards, Sebastian Nielsen

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Dovecot v2.3.4.1 Debian 10.3 mbox format - Error: chdir(/var/spool/mail/domain/user) failed: Not a directory
by vik 10 May '20

10 May '20

Hi colleagues, I am trying to setup dovecot and have a strange problem. I configured it to: #dovecot -n|grep ^mail mail_gid = mail mail_location = mbox:/var/spool/mail/%d/mailboxes/%n:INBOX=/var/spool/mail/%d/%n mail_uid = mail And also setup exim4 to use it. I sent a test message and observe a mailbox file /var/spool/mail/domain/user, containing this message. But when I try to access dovecot with a client (thunderbird), client cannot fetch mail, and I observe error in the dovecot's log: May 09 23:35:51 imap(user@domain)<25179><JNFIDz2ldeOsEAE3>: Error: chdir(/var/spool/mail/domain/user) failed: Not a directory What is it, and how to solve it? Thank you. Kind regards, Viktor

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ot: copy physical mail files ?
by Voytek Eymont 09 May '20

09 May '20

dumb question warning: I have two email accounts, me@tld1 and me@tld2 often, get emails intended (by me) for me@tld2 sent to me@tld1 this is purely for my own preferred record keeping preference, as I run the server, is it 'a really bad things' if I simply copy relevant mail files from /var/vmail/vmail1/tld1..../cur to /var/vmail/vmail1/tld2.../cur ? rather than forward emails as I have been doing? thanks

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What's a Reasonable Inbox Size?
by Asai 09 May '20

09 May '20

Greetings, I have several users who have inboxes that are over 20 GB. Lately I have noticed Dovecot logs say it's taking over 30 seconds to sync their mailboxes. As email admins, how do you handle inboxes that are so large? Do you use mailbox types that have better performance like dbox? We're using maildir. What's a reasonable inbox size? Is 20+ GB reasonable and nothing to worry about? Thanks for any insight here. -- Asai7

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Unable to disable TLSv1.3 or fallback to TLSv1.2 when 1 cipher is disabled
by Steve Egbert 09 May '20

09 May '20

I have an operational need to disable TLSv1.3 due to inadequate support to exclude certain ciphers. Much to my dismay, the `ssl_protocols` had been renamed and re-functionalized into `ssl_min_protocol`. Now, there is no way to exclude a specific group of one or more TLS versions. For a new bug report, I think we need two new settings: * `ssl_tls13_ciphersuite` and * `ssl_tls10_cipher` settings introduced into Dovecot for better granularity. ALong with support for fallback to TLSv1.2 as outlined in https://bugzilla.mozilla.org/show_bug.cgi?id=1250568 I'm still being hammered with the following error with Thunderbird 76.0b3, Dovecot 2.3.4.1-5+deb10u1, Debian 11: May 8 11:15:47 ns1 dovecot: imap-login: Debug: SSL: where=0x10, ret=1: before SSL initialization May 8 11:15:47 ns1 dovecot: imap-login: Debug: SSL: where=0x2001, ret=1: before SSL initialization May 8 11:15:47 ns1 dovecot: imap-login: Debug: SSL: where=0x2002, ret=-1: before SSL initialization May 8 11:15:47 ns1 dovecot: imap-login: Debug: SSL: where=0x2001, ret=1: before SSL initialization May 8 11:15:47 ns1 dovecot: imap-login: Debug: SSL alert: where=0x4008, ret=582: fatal protocol version May 8 11:15:47 ns1 dovecot: imap-login: Debug: SSL: where=0x2002, ret=-1: error May 8 11:15:47 ns1 dovecot: imap-login: Debug: SSL error: SSL_accept() failed: error:14209102:SSL routines:tls_early_post_process_client_hello:unsupported protocol May 8 11:15:47 ns1 dovecot: imap-login: Disconnected (disconnected before auth was ready, waited 0 secs): user=<>, rip=XX.XX.XX.XX, lip=XX.XX.XX.XX, TLS handshaking: SSL_accept() failed: error:14209102:SSL routines:tls_early_post_process_client_hello:unsupported protocol, session=<GN/GeCSlYuhEhl2U> May 8 11:15:47 ns1 dovecot: imap-login: Debug: SSL error: SSL_accept() syscall failed: Invalid argument This occurred when specifying one TLSv1.3 cipher to be excluded in ssl_cipher via an exclamation mark. On a side note of IMAP client, Latest Mozilla Thunderbird had its pref setting security.tls.version.fallback-limit to 4 (TLSv1.3), of which I have adjusted it to 3 (TLSv1.2) and it .... works when Dovecot is set to TLSv1.2. (Details of Thunderbird security.tls.version.fallback-limit is given in http://kb.mozillazine.org/Security.tls.version.* ) Steve

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