July 2020 - dovecot - dovecot.org

Dovecot Replication Errors (only) when using tcps: as the mail_replica Protocol
by Reuben Farrelly 18 Dec '20

18 Dec '20

Hi, I've been seeing errors logged for some time with replication processes, whereby replication sessions seem to be timing out periodically. This is with dovecot version 2.3.10.1 (a3d0e1171) and both are Gentoo x86_64. After some investigation I've determined that these timeouts are only ever occurring with tcps as the replication connection type. These errors never occur if non-encrypted tcp is configured. I've been able to validate this by changing only the replica_type on both ends of the replication configuration to tcp, and with no other changes and after a few days of operation there is not a single error logged. mail_replica = tcps:lightning.reub.net:4813 <<< periodic timeouts mail_replica = tcp:lightning.reub.net:4814 <<< works perfectly Example of the error: Jun 12 15:45:44 thunderstorm.reub.net dovecot[21149]: dsync-local(kaylene)<zx+WKTAU416UMwAAzkCIew>: Error: dsync(lightning.reub.net): I/O has stalled, no activity for 600 seconds (last sent=mailbox_delete, last recv=handshake) Jun 12 15:45:44 thunderstorm.reub.net dovecot[21149]: dsync-local(kaylene)<zx+WKTAU416UMwAAzkCIew>: Error: Timeout during state=recv_mailbox_tree doveadm: Error: Timeout during state=slave_recv_mailbox: 6 Time(s) doveadm: Error: Timeout during state=sync_mails (send=mail_requests recv=attributes): 31 Time(s) doveadm: Error: dsync(thunderstorm.reub.net): I/O has stalled, no activity for 600 seconds (last sent=mail_change (EOL), last recv=mailbox): 31 Time(s) doveadm: Error: dsync(thunderstorm.reub.net): I/O has stalled, no activity for 600 seconds (last sent=mailbox_delete, last recv=mailbox_delete): 6 Time(s) It is seen on both sides of the replication setup. The replica is offsite but only a few ms of latency away and there is no packet loss. The replication is happening over IPv6, and the local firewall is logging that sessions are always permitted, and only ever finishing due to tcp-fin or tcp-rst-from-client . SSL appears to be correctly configured, and it seems that the replication itself is for the most part working. Clients are able to use imaps just fine so I don't think there's anything much wrong from an SSL perspective else I'd be seeing complete replication failure and/or client devices unable to connect. Can anyone suggest how we can further debug this problem? Thanks, Reuben

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Repo for ubuntu focal 20.04 LTS
by Sébastien Riccio 27 Nov '20

27 Nov '20

Hello Dovecot, As the new ubuntu LTS 20.04 seems to be out, I would like to ask if there are any plans to add a repo like it already exists for 18.04 LTS. We planned to upgrade our 18.04 LTS boxes to 20.04. It has it’s own dovecot packages (2.3.7 at the time of writing this), but I would prefer we use your repositories like we do with 18.04. Kind regards, Sébastien

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Re: Dovecot permission denied errors on NFS after upgrade to 2.2.17
by Claudio Corvino 29 Sep '20

29 Sep '20

Thanks Jochen, no mixups present at all, file assigned to UID 501. Since this problem started few hours after the Debian upgrade, I think it is related to it. I don't know if something has changed on the NFS client side on Debian, but I don't think so as aptlistchanges didn't notify me about it, nor if Dovecot 2.2.17 treat NFS in other way. I'm stuck. On 13/07/20 16:07, Jochen Bern wrote: > On 07/13/2020 03:45 PM, Claudio Corvino wrote: >> in addition the "permission denied" error is >> random, most of the time Dovecot works well. > In *that* case, I'd say that UID/GID mapping problems can be ruled out. > >> How can I check the mappings NFS uses? > You don't have any relevant options in the client's fstab entry, and > I'll assume that there are none in the server's /etc/exports, either. > That leaves only potential default mappings, which should be documented > in the corresponding manpages. > > Also, since there's only *one* user/group involved, you can always > "chown" a test file on one side and check with "ls -n" on the other to > verify whether there are mixups. > > *Intermittent* failures of an NFS mount over a well-functioning LAN ... > I'm thinking "file locking" now, but that's a *complicated* topic, to > say the least ... > > https://en.wikipedia.org/wiki/File_locking#Problems > https://unix.stackexchange.com/questions/553645/how-to-install-nfslock-daem… > > Regards,

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Dovecot SASL
by Jorge Bastos 22 Sep '20

22 Sep '20

Howdy, I know i've asked this before, but i think i got really no answer. I'd like to have dovecot SASL, to check AUTH against an SQL table, instead of dovecot SASL use the AUTH MECH for imap/pop3. I want this, to have the same behavior as I have now, where i use postfix with cyrus SASL on a different table (with the same login details), and when i have an user that his accounts was hacked for sending spam, i just block the send and allow the user to keep receiving emails, for example to warn him. Would this be possible? Dovecot SASL against a SQL table? Havent found much info about it, Thanks in advanced,

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How to use dovecot only as POP3 server / prevent it from creating .imap directories?
by Binarus 18 Sep '20

18 Sep '20

Dear all, on our mail server, I let sendmail deliver incoming messages to a file in mbox format called "inbox" in each user's home directory. Now I would like to use dovecot as POP3 server so that users can let their MUA download their messages via POP3. I do not want to use any IMAP functionality. The POP3 part works with the configuration shown below, but nevertheless there is a problem which is a show stopper: Although I think I have turned off IMAP (e.g. no IMAP listener), dovecot still creates .imap directories and does so in a very weird way. It creates one .imap subdirectory in every subdirectory of each user's home directory, and for every file in each user's home directory creates an additional subdirectory with the same name in its .imap directories. It does this recursively, and 1000 files in a user's home directory would mean 1000 additional subdirectories. Of course, I can't live with that. I know that the dovecot documentation discourages using the home directory as mail location, but in my case this should not be a problem at all if IMAP is not used. I have played around with dovecot for several days, but could not solve that problem. So how can I turn off IMAP completely and prevent dovecot from creating any .imap directories or IMAP related files? This happens with dovecot 2.3.4.1 (f79e8e7e4) on Debian buster (with all updates applied). My configuration (doveconf -n) is (the configuration is complete - I don't use SQL or LDAP): # 2.3.4.1 (f79e8e7e4): /etc/dovecot/dovecot.conf # Pigeonhole version 0.5.4 () # OS: Linux 4.19.0-9-amd64 x86_64 Debian 10.4 # Hostname: host.example.com listen = aaa.bbb.ccc.ddd mail_location = mbox:~:INBOX=~/inbox mail_privileged_group = mail 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 } pop3_lock_session = yes protocols = " pop3" service imap-login { inet_listener imap { port = 0 } inet_listener imaps { port = 0 } } service pop3-login { inet_listener pop3 { port = 0 } inet_listener pop3s { port = 995 ssl = yes } } ssl = required ssl_cert = </etc/dovecot/tls/xxxx.crt ssl_cipher_list = DHE-RSA-AES256-GCM-SHA384 ssl_client_ca_dir = /etc/ssl/certs ssl_dh = # hidden, use -P to show it ssl_key = # hidden, use -P to show it ssl_min_protocol = TLSv1.2 ssl_prefer_server_ciphers = yes userdb { driver = passwd } Thank you very much in advance for any idea! Regards, Binarus

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LMTP-Process stays in RCPT TO state
by Pascal Christen 07 Sep '20

07 Sep '20

Hi We tried to update our Dovecot Director-Ring to 2.3 (latest version) and had one problem/bug. When we try to deliver an email from Exim to a receiving Dovecot (2.3 latest) via the LMTP-Proxy the LMTP process stays open forever and never closes. So after a few hours, we hit the LMPT-Process limit. The problem only exists if the receiving Dovecot reports "Quota exceeded (mailbox for user is full)" back to the Exim. If this is the case the state on the LMPT process stays at "lmtp: [_IP_ RCPT TO] (lmtp) and never closes. The TCP-Connection to the Exim is then in CLOSE_WAIT state on the Proxy. On the receiving Dovecot we set the "lmtp_rcpt_check_quota=yes" option. For me, it sounds similar to this bug: https://dovecot.org/list/dovecot/2018-January/110697.html but without the SEGFAULT which makes it harder to debug it. May you guys know why it doesn't change the state to IDLE or READY after reporting the quota issue or see something fishy in the commit above. If not I try to get a trace of the hanging process. Greetings Pascal

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How to backup maildir
by Robert Moskowitz 04 Sep '20

04 Sep '20

I have been thinking, and reading, on how to back up my mailserver. I have not found any approach that seems ready to use. I have run years without any backup, but would really like to have something in place. I figure I can attach a USB drive and backup to that, then from there rsync to something elsewhere. Further if that USB drive is a full mailserver image, I actually have a 'hot backup' where I only have to put the backup drive into a system and boot up at the last backup. But this means properly copying all of /home/vmail and probably /home/sieve plus the /var/lib/mysql Are there good tools that nicely does this? Or do I choose a time late at night (only I am sometimes in non-US timezones) to shut down all services and just use rsync? And stopping services itself is thought provoking. What if Dovecot, amavis, mysql, or whatelse is in the middle of writing out a mail file what happens to that file and restart. Just scary stuff and, in part, why I have never tackled this in the past. thanks for all feedback

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Rootless wiki page is not up to date?
by Marc Roos 20 Aug '20

20 Aug '20

If I run a docker image with the mesos containerizer and altering the dovecot config mentioned here[1] I think the root detection is incorrect because it looks like dovecot is still thinking it is root. I still get errors like: >> log(829825): Fatal: We couldn't drop root group privileges (wanted=10053(dovecot), gid=0(root), egid=0(root)) Why does it want to drop to root, if we are not even running as root? >> Error: service(ipc): chown(/var/dovecot/login/ipc-proxy, 91, 4294967295) failed: Operation not permitted Why does it want to chown, when it is not root? pop3-login: Fatal: setgid(101(dovenull)) failed with euid=10053(dovecot), gid=10053(dovecot), egid=10053(dovecot): Operation not permitted (This binary should probably be called with process group set to 101(dovenull) instead of 10053(dovecot)) [1] https://wiki.dovecot.org/HowTo/Rootless?action=edit&editor=text

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Correcting Mail Home, Maildir and Sieve folder locations
by David White 13 Aug '20

13 Aug '20

I have Dovecot 2.3.7.2 on Ubuntu 20.04. I just migrated the server from CentOS 8, and only migrated to the CentOS 8 machine a few months ago off of CentOS 7. I am pasting `doveconf -n` at the bottom of this email. Everything is working. However, I'm trying to clean up warnings in the logs, and just discovered that I'm not managing home directories properly. (c/f https://wiki.dovecot.org/VirtualUsers/Home) This is in the logs: > Jun 28 06:09:50 mail.example.com dovecot: imap(email(a)example.com)<3786><fICEJCKpbfatQHg1>: Error: stat(/var/vmail/example.com/email@example.com/.dovecot.sieve/tmp) failed: Not a directory Can I please get a sanity check? To resolve, I've come up with a bash loop to create a home folder, and fix the existing structure for each mailbox on the system. I ran this for 1 of the domains on the system. > for i in */ ; do mv "$i" mail; mkdir "$i"; mv mail "$i"; mv "$i"/.dovecot* "$i"; done Then, I would simply edit /etc/dovecot/conf.d/10-mail.conf so that it looks like this: > mail_home = /var/vmail/%d/%u > mail_location = maildir:/var/vmail/%d/%u/mail To confirm, should all of the 'hidden' dovecot files be moved to the user's new home folder like I'm trying to do in the above script? Or are there other files that I will need to move? After running that loop above on a test server (don't worry, I would never do this in production without testing), one of the mailbox's home folder on the server looks like this: > total 56 > drwxr-xr-x 4 vmail vmail 4096 Jun 28 06:19 . > drwx------ 6 vmail vmail 4096 Jun 28 06:09 .. > -rw------- 1 vmail vmail 54 Jul 4 2019 .dovecot.lda-dupes > lrwxrwxrwx 1 vmail vmail 21 May 26 2016 .dovecot.sieve -> sieve/roundcube.sieve > -rw------- 1 vmail vmail 0 Oct 17 2016 .dovecot.sieve.log > -rw------- 1 vmail vmail 218 Jul 6 2019 .dovecot.svbin > drwx------ 277 vmail vmail 32768 Jun 28 06:19 mail > drwx------ 3 vmail vmail 4096 Feb 2 17:31 sieve ... and connecting to that mailbox over Thunderbird seems to be working fine. But I want to make sure I'm not missing anything. Here is my doveconf -n, with identifying information snipped out: > root@mail:# doveconf -n > # 2.3.7.2 (3c910f64b): /etc/dovecot/dovecot.conf > # Pigeonhole version 0.5.7.2 () > # OS: Linux 5.4.0-39-generic x86_64 Ubuntu 20.04 LTS ext4 > # Hostname: {snip} > auth_mechanisms = plain login > mail_location = maildir:/var/vmail/%d/%u > managesieve_notify_capability = mailto > managesieve_sieve_capability = 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 mime foreverypart extracttext > namespace inbox { > inbox = yes > location = > mailbox Drafts { > auto = subscribe > special_use = \Drafts > } > mailbox Junk { > special_use = \Junk > } > mailbox Sent { > auto = subscribe > special_use = \Sent > } > mailbox "Sent Messages" { > special_use = \Sent > } > mailbox Spam { > auto = create > special_use = \Junk > } > mailbox Trash { > auto = subscribe > special_use = \Trash > } > prefix = > } > passdb { > args = /etc/dovecot/dovecot-sql.conf.ext > driver = sql > } > plugin { > sieve = file:~/sieve;active=~/.dovecot.sieve > } > protocols = imap pop3 lmtp sieve > service auth-worker { > user = $default_internal_user > } > service auth { > unix_listener /var/spool/postfix/private/auth { > group = postfix > mode = 0666 > user = postfix > } > unix_listener auth-userdb { > group = postfix > mode = 0666 > user = vmail > } > } > service lmtp { > unix_listener /var/spool/postfix/private/dovecot-lmtp { > group = postfix > mode = 0666 > user = postfix > } > } > ssl = required > ssl_ca = </etc/ssl/certs/snip.ca-bundle > ssl_cert = </etc/ssl/certs/snip.crt > ssl_cipher_list = ALL:!LOW:!SSLv3:!EXP:!aNULL:!MD5 > ssl_key = # hidden, use -P to show it > userdb { > args = uid=vmail gid=vmail home=/var/vmail/%d/%u > driver = static > } Sent with ProtonMail Secure Email.

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Can't move/delete folder "Renaming not supported across conflicting directory permissions"
by Johannes Rohr 12 Aug '20

12 Aug '20

Dear all, several users have reported that they were unable to move/delete folders using Thunderbird and they got the message "Renaming not supported across conflicting directory permissions". When I google for this message, I see hints like "your mail may not be all on the same volume", but here this is definitely not the case. All mail is in /var/mail/virtual and owned by mail:mail Curiously, when I tried the same operation in Roundcube, there was no error reported, so something about the combination of Thunderbird and Dovecot seems to be causing the error. Does anyone have advise on how I should go about tracking down the cause of the error? Thanks a lot in advance! Johannes

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