- dovecot - dovecot.org

Multiple backends with NFSv4.1 (supports file locking): should work without Director, right?
by pierre.alletru＠gmail.com 05 Jun '23

05 Jun '23

Hi Dovecot community, We're looking at running multiple Dovecot backend servers in parallel, all using the same shared NFSv4.1 mount to store mailboxes in the maildir format. We've read in multiple places that running multiple backends with a shared NFS can result in issues like index files corruption. The standard solution seems to use the Director feature, or some kind of IP based proxy/load balancer. But: 1 - The Director feature will be removed in future free versions of Dovecot (https://dovecot.org/mailman3/archives/list/dovecot@dovecot.org/thread/ILA3C…) 2 - NFSv4 and above support file locking (flock and fcntl, flock being emulated using fcntl). 3 - It looks like Dovecot does use file locking, though we're unsure if it does on everything and in particular on index files. Thus, we are wondering if the need for Director is still relevant with NFSv4? Shouldn't it work without Director thanks to file locking? Has anyone tried it? We're thinking that the documentation and various threads on the subject may be outdated, based on NFSv3 and lower (no file locking). If it doesn't work, anybody knows why? Isn't file locking there precisely to handle concurrency? Thanks!

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attachments storage sub folders
by cor＠soverin.net 04 Jun '23

04 Jun '23

Hi all, we're using a separate attachment storage. Is there a way to control the subfolders that are created for each attachment? Currently the path is <user subfolder>/XX/YY/XXYY<hash>. In practice this means almost every single attachment gets its own 2 subfolders XX/YY. I'm seeing users with 5000 attachments and almost 10.000 folders. Normally this wouldn't be that big of a deal but we're using ZFS storage with metadata special device and this is causing a huge amount of additional folder metadata. It would already be helpful if we could just have a single XX/XX<hash> subfolder per user. Is that possible? Thanks, Cor dovecot 2.3.20 mail_attachment_dir = /data/attachments/%{userdb:folder} mail_attachment_fs = posix mail_attachment_hash = %{sha256:160} mail_attachment_min_size = 128k

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Share
by liecj3＠bfh.ch 01 Jun '23

01 Jun '23

Hello dear Dovecot users I have a somewhat special request: I have a single file in mbox format which I want to make accessible via IMAP to anonymous logins. The mbox file is being updated outside of Dovecot and should not be changeable by Dovecot. So far I created a Docker container based on the official image (https://hub.docker.com/r/dovecot/dovecot) and configured the Dovecot according to https://doc.dovecot.org/configuration_manual/shared_mailboxes/public_shared/. The volume with the mbox file is mounted in the running container under /var/mail. Each time a client tries to access this public mailbox the following error is logged and no content is returned: May 26 21:57:06 imap(mutt)<16><Rkpg0Z/8pLfAqDAB>: Error: Mailbox Public/archive: open() failed with mbox: Read-only file system. Note that I don't need the file to be a shared mailbox. Instead I would also be happy to have all (anonymous) users mapped to the read-only mbox somewhere in the filesystem. Dockerfile: FROM dovecot/dovecot RUN mkdir -p /var/indexes/public RUN chown 1000:1000 /var/indexes/public ADD dovecot.conf /etc/dovecot/dovecot.conf /etc/dovecot/dovecot.conf: ## You should mount /etc/dovecot if you want to ## manage this file mail_home=/srv/mail/%Lu mail_location=sdbox:~/Mail mail_uid=1000 mail_gid=1000 #protocols = imap pop3 submission sieve lmtp protocols = imap first_valid_uid = 1000 last_valid_uid = 1000 passdb { driver = static args = password=pass } ssl=yes ssl_cert=<cert.pem ssl_key=<key.pem namespace { type = private inbox = yes separator = / } namespace { type = public prefix = Public/ location = mbox:/var/mail/:INDEX=/var/indexes/public subscriptions = no } listen = * log_path=/dev/stdout info_log_path=/dev/stdout debug_log_path=/dev/stdout

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Using "forward_" variables in last_login_key
by Eirik Rye 01 Jun '23

01 Jun '23

Hello, In my setup, I am running dovecot with the following last_login config: plugin { last_login_dict = file:~/.last_login last_login_key = %s } I would like to distinguish between logins through webmail (Roundcube) and logins through regular IMAP clients. Roundcube sends "x-forward-service=webmail" in ID, and I have working logging for this by putting the following in login_log_format_elements: service=%{if;%{passdb:forward_service};eq;webmail;webmail;%s} (Is there may be a more elegant way to do this conditional?) This will print `service=webmail` for webmail logins, and `service=imap` for regular IMAP client logins. However, the same conditional does not work in last_login_key: last_login_key = %{if;%{passdb:forward_service};eq;webmail;webmail;%s} Using this, the login fails and the error log outputs the following error: Error: Failed to expand plugin setting last_login_key = '%{if;%{passdb:forward_service};eq;webmail;webmail;%s}': Unknown variable '%passdb' How can I tell which variables are available to use in this plugin? Are the forwarded variables not available? If not, any other suggestions on how to differentiate these logins in last_login? Looking at the remote_ip is not feasible for my setup. Best regards, Eirik

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GSSAPI auth Line too long
by Thomas Lemarchand 31 May '23

31 May '23

Hello, On version 2.3.20 (80a5ac675d), I have a problem with submission-login when using GSSAPI auth : it's not working, probably due to AUTH line being too long. It appeared after I activated PAC on my Kerberos infrastructure. Now the Kerberos tickets contains MS-PAC data and are bigger. It's part of the RFC and is a valid use case : https://datatracker.ietf.org/doc/html/rfc4120#section-5.2.6 Logs : May 30 17:13:00 auth: Debug: auth client connected (pid=378) May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: Sent: 220 mail.int.k8s.lemarchand.io Dovecot ready. May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: Received new command: EHLO [192.168.202.16] May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: command EHLO: New command May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: command EHLO: Execute command May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: command EHLO: Pipeline blocked May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: command EHLO: 250 reply: Submitted May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: command EHLO: Replied May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: command EHLO: Ready to reply May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: Trigger output May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: command EHLO: Next to reply May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: Sending replies May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: command EHLO: Next to reply May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: command EHLO: Completed May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: command EHLO: Pipeline unblocked May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: Connection state reset May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: command EHLO: 250 reply: Sent: 250-mail.int.k8s.lemarchand.io 8BITMIME AUTH GSSAPI PLAIN LOGIN BURL imap CHUNKING ENHANCEDSTATUSCODES SIZE P IPELINING May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: command EHLO: Finished May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: command EHLO: Destroy May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: command EHLO: 250 reply: Destroy May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: Trigger output May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: No more commands pending May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: Sending replies May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: No more commands pending May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: Client sent invalid command: Command line is too long May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: command [unknown]: Invalid command May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: command [unknown]: 500 reply: Submitted May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: command [unknown]: Replied May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: command [unknown]: Ready to reply May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: Trigger output May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: Sending replies May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: command [unknown]: Next to reply May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: command [unknown]: Completed May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: command [unknown]: 500 reply: Sent: 500 5.5.2 Line too long May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: command [unknown]: Finished May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: command [unknown]: Destroy May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: command [unknown]: 500 reply: Destroy May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: Trigger output May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: No more commands pending May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: Sending replies May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: No more commands pending May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: Remote closed connection: Connection closed May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: Disconnected: Connection closed May 30 17:13:00 submission-login: Debug: smtp-server: conn 10.200.114.128:13587 [1]: Connection state reset My guess is that it's due to https://github.com/dovecot/core/blob/main/src/lib-smtp/smtp-common.h#L10 being too low (is it configurable ?), but I didn't read the code thoroughly. Red Hat IDM now activates MS-PAC by default, so any installation based on IDM (or FreeIPA) may have the same problem. What's your opinion ? Bug ? Mail sent using password auth :'( -- Thomas Lemarchand

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Inconsistent listing of shared subfolders
by mschering＠intermesh.nl 30 May '23

30 May '23

Hi all, I have a problem with listing shared folders. In my web application I don't get the whole folder tree at once but get them level by level with: LIST "" "subfolder/%" RETURN (CHILDREN) Now I have an issue with shared folders. If I share folder test/sub with another user it returns it's (not shared) parent folder with this command: LIST "" "shared/someuser/%" RETURN (CHILDREN) But if I do the same with INBOX/sub it will not return the "INBOX" folder with the above command. Is that a bug or does anybody know why it behaves differently? Also, If I do: LIST "" "shared/someuser/*" RETURN (CHILDREN) it will return both the subfolder of test and inbox. My shared namespace is setup like this: namespace { type = shared separator = / prefix = shared/%%u/ # a) Per-user seen flags. Maildir indexes are shared. (INDEXPVT requires v2.2+) location = maildir:%%h/Maildir:INDEXPVT=~/Maildir/shared/%%u # b) Per-user seen flags. Maildir indexes are not shared. If users have direct filesystem level access to their mails, this is a safer option: #location = maildir:%%h/Maildir:INDEX=~/Maildir/shared/%%u:INDEXPVT=~/Maildir/shared/%%u subscriptions = no list = children } Thanks for any help! Best regards, Merijn

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Outlook Duplicate emails
by Nick Lekkas 29 May '23

29 May '23

Hello there to all ! I have 2 postfix/dovecot mailservers. Those mailservers are synced using replicator enabled. The dovecot versions I use is 2.3.16 on Rocky Linux 9 .The configuration issued from CentOS 7 mailservers with replicator enabled using 2.2.36. The config is the same in both 2 couple servers. I have issue with pop3 and outlook that receives duplicate email in many cases and in some accounts. Have anyone faced any similar issue.? Any help appreciated... Best Regards Nick __________ ESET Endpoint Antivirus __________ This email was scanned, no threats were found. email from: to: with subject Outlook Duplicate emails dated 29/05/2023 - is OK Detection engine version: 27314 (20230529) https://www.eset.com

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RE: LDAP olcAccess for auth_bind
by Marc 29 May '23

29 May '23

> >> > >> I really got your point, but how you will implement aliases > > has nothing to do with dovecot, sendmail can get those from ldap. > > > >> or domain > > sendmail gets these from ldap (but requires a restart) > > > >> query or maybe quota? You still need to access ldap directly for > other > >> info's. > > quotas can be/are distributed to the os by ldap. But it depends a bit > on your setup, and if you have multiple file systems. > > > >> I mean, dovecot can probably use linux login but i'm not sure about > the > >> MTA. Unless you have a fixed list of domains added manually. > >> > > I have on different servers cron jobs running, getting every 5?min > modified/created records and then do a restart or something else. All > these processes have own entity in ldap with own acls. > > sendmail can get anything you want from ldap. For outgoing mail auth, > I have sendmail use os users (which come from ldap) > > > So in the end you still access ldap from another program but not from > dovecot :) I don't get your point. The goal for using ldap is having a centralized database that distributes information. How you choose to implement this, is depending on your requirements. > You avoid to authenticate users directly only to send the credentials of > some privilleged user from postfix/sendmail/whatever script... > Not to avoid. Other applications have different needs and thus different acl's. Dovecot does not need to know a users email address or alias. Only the MTA needs to know. The relaying MTA does not need to know the user etc.

1 0

LDAP olcAccess for auth_bind
by Andrzej Milewski 28 May '23

28 May '23

Hi, I'm trying to set up a production mail server. I have installed Dovecot on Debian from the package. For authentication, I have another machine running OpenLDAP, also installed on Debian. I would like the end mail client to authenticate with Dovecot using the login and password set in LDAP. In the LDAP-related configuration, I have: auth_bind=yes base = ou=Users,dc=example,dc=com user_attrs = mail=couriermaildir:~/Maildir,homeDirectory=/home/%d/%uid/,uidNumber=uid,gidNumber=gid user_filter = (&(objectClass=posixAccount)(uid=%u)) pass_attrs = uid=user,userPassword=password,\ pass_filter = (&(objectClass=posixAccount)(uid=%u)) The LDAP user is entered as uid=user(a)example.com. With the default olcAccess permissions, it works and logs in correctly. Here are my default olcAccess settings after installation: # {1}mdb, config dn: olcDatabase={1}mdb,cn=config objectClass: olcDatabaseConfig objectClass: olcMdbConfig olcDatabase: {1}mdb olcDbDirectory: /var/lib/ldap olcSuffix: dc=example,dc=com olcAccess: {0}to dn.children="ou=Idmaps,dc=example,dc=com" attrs=userPassword, shadowLastChange,SambaLMPassword,SambaNTPassword by self write by anonymous a uth by dn="cn=samba,dc=example,dc=com" write by dn="cn=admin,dc=laktopol,dc=p l" write by * none olcAccess: {1}to dn.subtree="ou=Idmaps,dc=example,dc=com" by self write by dn= "cn=samba,dc=example,dc=com" write by dn="cn=admin,dc=example,dc=com" write b y * read olcAccess: {2}to dn.children="ou=Hosts,dc=example,dc=com" attrs=userPassword,s hadowLastChange,SambaLMPassword,SambaNTPassword by self write by anonymous au th by dn="cn=samba,dc=example,dc=com" write by dn="cn=admin,dc=example,dc=com " write by * none olcAccess: {3}to dn.subtree="ou=Hosts,dc=example,dc=com" by self write by dn=" cn=samba,dc=example,dc=com" write by dn="cn=admin,dc=example,dc=com" write by * read olcAccess: {4}to dn.children="ou=Users,dc=example,dc=com" attrs=userPassword,s hadowLastChange,SambaLMPassword,SambaNTPassword by self write by anonymous au th by dn="cn=samba,dc=example,dc=com" write by dn="cn=nsspam,dc=laktopol,dc=p l" write by dn="cn=admin,dc=example,dc=com" write by * none olcAccess: {5}to dn.children="ou=Users,dc=example,dc=com" by self write by dn= "cn=samba,dc=example,dc=com" write by dn="cn=nsspam,dc=example,dc=com" write by dn="cn=admin,dc=example,dc=com" write by * read olcAccess: {6}to filter=(objectClass=sambaDomain) by dn="cn=samba,dc=laktopol, dc=pl" write by dn="cn=admin,dc=example,dc=com" write by * read olcAccess: {7}to dn.base="dc=example,dc=com" attrs=children by dn="cn=samba,dc =laktopol,dc=pl" write by dn="cn=admin,dc=example,dc=com" write by * read olcAccess: {8}to attrs=userPassword,shadowLastChange,SambaLMPassword,SambaNTPa ssword by self write by anonymous auth by dn="cn=nsspam,dc=example,dc=com" wr ite by dn="cn=admin,dc=example,dc=com" write by * none olcAccess: {9}to attrs=shadowLastChange by self write by * read olcAccess: {10} to * by * read However, I am not satisfied with these settings because using the anonymous user, anyone can browse the entire LDAP tree. While passwords are not visible with anonymous login, user data in the LDAP domain is exposed. If I change the last olcAccess entry from "olcAccess: {10} to * by * read" to "olcAccess: {10} to * by anonymous auth," the anonymous user cannot browse LDAP, but the mail client user also cannot log in. What should be the correct configuration? -- Andrzej

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Outlook fails to connect to Dovecot submission server
by Ralf Becker 28 May '23

28 May '23

Dovecot 2.3.20 including it's submission server works well with all sorts of clients, but Outlook. Outlook works / can connect to Dovecot IMAP service with same certificate TLS config, but it fails to connect using SMTPs on port 465. Other clients connect and send mails without problem, also openssl s_client can connect and reports no problems. I tried with Outlook Version 365 on Windows 11 (no cloud) and "Microsoft® Outlook® 2021 MSO (Version 2304 Build 16.0.16327.20200) 64-bit". I already enabled all submission_client_workarounds and lowered min_ssl_version from TLSv1.2 to TLSv1, but that changed nothing. I can see nothing failing in the logs, thought the OL connection wizard always check IMAP and SMTP together, so it's hard to say what the problem is. The same two Outlook version connect without a problem to Postfix authenticating via SASL to Dovecot also requiring a minimum TLS version of 1.2. They just wont connect with Dovecot submission server. Any ideas what's wrong, or how to debug that further? Ralf -- Ralf Becker EGroupware GmbH [www.egroupware.org] Handelsregister HRB Kaiserslautern 3587 Geschäftsführer Birgit und Ralf Becker Leibnizstr. 17, 67663 Kaiserslautern, Germany Telefon +49 631 31657-0

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