- dovecot - dovecot.org

Office 365 SSL issue
by Ervin Hegedüs 23 Oct '22

23 Oct '22

Hi there, I have a bit old Dovecot instance (Ubuntu 14.04 - there is no chance to upgrade it), with these versions of packages: * Dovecot: 2.2.9 * OpenSSL: 1.0.1f Few days ago a client noticed me, that he can't reach his mails through his Office 365. He uses POP3S. I tried to set up a same client for this Dovecot server, but when I configured the POP3 protocoll, after the settings check Office says: Your server does not support the connection encryption type you have specified. Try changing the encryption method. Contact your mail server ... While the client was trying, I see these lines in the log: Oct 21 16:12:18 mail dovecot: pop3-login: Debug: SSL: where=0x10, ret=1: before/accept initialization [192.168.8.133] Oct 21 16:12:18 mail dovecot: pop3-login: Debug: SSL: where=0x2001, ret=1: before/accept initialization [192.168.8.133] Oct 21 16:12:18 mail dovecot: pop3-login: Debug: SSL: where=0x2001, ret=1: SSLv3 read client hello A [192.168.8.133] Oct 21 16:12:18 mail dovecot: pop3-login: Debug: SSL: where=0x2001, ret=1: SSLv3 write server hello A [192.168.8.133] Oct 21 16:12:18 mail dovecot: pop3-login: Debug: SSL: where=0x2001, ret=1: SSLv3 write certificate A [192.168.8.133] Oct 21 16:12:18 mail dovecot: pop3-login: Debug: SSL: where=0x2001, ret=1: SSLv3 write key exchange A [192.168.8.133] Oct 21 16:12:18 mail dovecot: pop3-login: Debug: SSL: where=0x2001, ret=1: SSLv3 write server done A [192.168.8.133] Oct 21 16:12:18 mail dovecot: pop3-login: Debug: SSL: where=0x2001, ret=1: SSLv3 flush data [192.168.8.133] Oct 21 16:12:18 mail dovecot: pop3-login: Debug: SSL: where=0x2002, ret=-1: SSLv3 read client certificate A [192.168.8.133] Oct 21 16:12:18 mail dovecot: pop3-login: Debug: SSL: where=0x2002, ret=-1: SSLv3 read client certificate A [192.168.8.133] Oct 21 16:12:18 mail dovecot: pop3-login: Warning: SSL failed: where=0x2002: SSLv3 read client certificate A [192.168.8.133] Oct 21 16:12:18 mail dovecot: pop3-login: Disconnected (no auth attempts in 0 secs): user=<>, rip=192.168.8.133, lip=192.168.8.21, TLS handshaking: Disconnected, session=<9sWMB4zr+ADAqAiF> Which is weird, because I disabled SSLv3. Here is the (relevant) config: ssl_cert = </etc/dovecot/dovecot.crt ssl_key = </etc/dovecot/dovecot.key ssl_dh_parameters_length = 2048 ssl_protocols = !SSLv2 !SSLv3 ssl_cipher_list = ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:AES:CAMELLIA:DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA verbose_ssl = yes When I check the supported encryption type with nmap, I get this: $ nmap --script ssl-enum-ciphers -p 995 192.168.8.21 Starting Nmap 7.80 ( https://nmap.org ) at 2022-10-22 10:20 CEST Nmap scan report for 192.168.8.21 Host is up (0.021s latency). PORT STATE SERVICE 995/tcp open pop3s | ssl-enum-ciphers: | TLSv1.0: | ciphers: | TLS_DHE_RSA_WITH_AES_128_CBC_SHA (dh 2048) - A | ... | TLSv1.1: | ciphers: | TLS_DHE_RSA_WITH_AES_128_CBC_SHA (dh 2048) - A | ... | TLSv1.2: | ciphers: | TLS_DHE_RSA_WITH_AES_128_CBC_SHA (dh 2048) - A | ,,, |_ least strength: C When I check the traffic with tcpdump, I see that client uses TLSv1.2: https://www.dropbox.com/s/k8wqzg5xzki5p23/pop3_traffic.png Only the one client who reported the problem, and my test client can't reach the server - other (about) 400 users can (but I don't know with what kind of types of clients - most use Thunderbird). What can I do? How can I fix this problem? As I wrote, this problem has came few days ago suddenly... Thanks, a.

4 5

Change password schema and post-login script
by Christos Chatzaras 23 Oct '22

23 Oct '22

Hello, Question #1: For version 2.3.19.1 these commands use BLF-CRYPT, right? doveadm pw doveadm pw -s CRYPT Question #2: I want to change password schema for current users. For users using POP3 or IMAP I can do it using a post-login script. I have some accounts used only to send e-mails using Postfix, so no POP3/IMAP logins for these accounts. Is any way to change password schema for these accounts? My config: # 2.3.19.1 (9b53102964): /usr/local/etc/dovecot/dovecot.conf # Pigeonhole version 0.5.19 (4eae2f79) # OS: FreeBSD 13.1-RELEASE-p2 amd64 zfs # Hostname: server2.example.com auth_master_user_separator = * auth_mechanisms = plain login auth_verbose = yes default_process_limit = 225 disable_plaintext_auth = no first_valid_gid = 0 first_valid_uid = 1001 mail_location = maildir:/home/mail/%d/%n:INDEX=/tmpfs/dovecot_%u:CONTROL=/var/mail/%d/%n mail_privileged_group = mail 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 imapsieve vnd.dovecot.imapsieve namespace inbox { inbox = yes location = mailbox Drafts { auto = subscribe special_use = \Drafts } mailbox Junk { auto = subscribe special_use = \Junk } mailbox Sent { auto = subscribe special_use = \Sent } mailbox "Sent Messages" { auto = no special_use = \Sent } mailbox Trash { auto = subscribe special_use = \Trash } prefix = } passdb { args = /usr/local/etc/dovecot/passwd.master driver = passwd-file master = yes result_success = continue } passdb { args = /usr/local/etc/dovecot/passwd.suspended deny = yes driver = passwd-file } passdb { args = /usr/local/etc/dovecot/passwd driver = passwd-file } plugin { imapsieve_mailbox1_before = file:/usr/local/lib/dovecot/sieve/report-spam.sieve imapsieve_mailbox1_causes = COPY imapsieve_mailbox1_name = Junk imapsieve_mailbox2_before = file:/usr/local/lib/dovecot/sieve/report-ham.sieve imapsieve_mailbox2_causes = COPY imapsieve_mailbox2_from = Junk imapsieve_mailbox2_name = * quota = maildir:User quota quota_max_mail_size = 100M quota_rule = *:storage=2048M quota_status_nouser = DUNNO quota_status_overquota = 552 5.2.2 Mailbox is full quota_status_success = DUNNO quota_warning = storage=80%% quota-warning 80 %u sieve = file:~/sieve;active=~/sieve.active sieve_before = /usr/local/lib/dovecot/sieve/antispam.sieve sieve_global_extensions = +vnd.dovecot.pipe sieve_pipe_bin_dir = /usr/local/lib/dovecot/sieve sieve_plugins = sieve_imapsieve sieve_extprograms } protocols = imap pop3 lmtp sieve service auth { client_limit = 1125 unix_listener auth-client { group = postfix mode = 0660 user = postfix } } service lmtp { unix_listener /var/spool/postfix/private/dovecot-lmtp { group = postfix mode = 0600 user = postfix } } service managesieve-login { inet_listener sieve { address = 127.0.0.1 port = 4190 } } service quota-status { client_limit = 1 executable = quota-status -p postfix inet_listener { port = 12340 } } service quota-warning { executable = script /root/cretapanel/quota-warning.sh unix_listener quota-warning { mode = 0666 user = dovecot } } ssl_cert = </etc/ssl/certs/mail.pem ssl_dh = # hidden, use -P to show it ssl_key = # hidden, use -P to show it ssl_min_protocol = TLSv1.2 userdb { args = /usr/local/etc/dovecot/passwd driver = passwd-file } verbose_proctitle = yes protocol imap { imap_client_workarounds = delay-newmail tb-extra-mailbox-sep mail_max_userip_connections = 20 mail_plugins = quota imap_quota imap_sieve imap_zlib } protocol pop3 { mail_plugins = quota pop3_client_workarounds = outlook-no-nuls oe-ns-eoh pop3_uidl_format = %08Xu%08Xv } protocol lda { postmaster_address = postmaster(a)example.com sendmail_path = /usr/sbin/sendmail } protocol lmtp { mail_plugins = quota sieve postmaster_address = postmaster(a)example.com }

3 2

dovecot mailing list (this mailing list), DKIM, SPF and DMARC
by Lev Serebryakov 22 Oct '22

22 Oct '22

My domain (serebrtyajov.spb.ru) has all these "new" e-mail technologies configured. It works fine till I write to this mailing list. After that I've got several DMARC reports about "spam" from my domain. All these reports are about my mailing list post. I don't have such problems with other mailing lists (FreeBSD ones, OpenJDK ones, and others). Looks like mailing list software for this mailing list is misconfigured. I'm sure, I'll get new after this message. -- // Black Lion AKA Lev Serebryakov

15 38

lmtp userdb can't resolve users
by George Asenov 21 Oct '22

21 Oct '22

Hello, I use postfix with dovecot as an lmtp LDA with unix users and multiple domain names and mailboxes in Maildir format placed in domain directory like: /home/mainuser/homes/user(a)domain.tld/Maildir or /home/mainuser/domains/domain2.tld/homes/user(a)domain2.tld/Maildir which have the main user as a group and user@domain.tld/user@domain2.tld as owner Postfix have virtual_alias_maps = hash:/etc/postfix/virtual there in virtual file there is map like: user(a)domain.tld user-domain(a)domain.tld and in /etc/passwd there are actually 2 users with the same home dir and same UID/GID (only the username is different) and in postfix mailbox_transport = lmtp:unix:private/dovecot-lmtp The issue is that when postfix passes the email for local delivery to dovecot lmtp it sends the username as user-domain.tld(a)serverhostname.tld but dovecot is configured with !include auth-system.conf.ext can't resolve this username thus fails to deliver. I've found a workaround in the net to use custom userdb just for lmtp like this: protocol lmtp { mail_plugins = $mail_plugins sieve userdb { driver = passwd-file args = username_format=%n /etc/passwd } } which works but produce some warnings because there is the root user (ID 0) and actually is a dirty workaround Is there more elegant solution??

2 1

sieve script is too large (max 1048576 bytes)
by Marc 19 Oct '22

19 Oct '22

In what section of the config is this limited? I assume it is related to this >go1.13 memory model that allocates quite a lot of vsz?

3 3

mdbox vs. maildir format
by Michael 19 Oct '22

19 Oct '22

hey, i am considering changing my mailbox format from maildir to mdbox. the reason for this is mainly, b/c i have (a) multiple large mailboxes with tens of thousands of mail files, and (b) most of these mails files have a size significantly smaller than the sector size of the disk. so, since the emails themselves are only about nGB large, the disk space used is at least twice as much, if not even three times. i know, hard disk space is 'cheap', but still... but then i read at https://doc.dovecot.org/admin_manual/mailbox_formats/dbox/ the following: [...] you must not lose the dbox index files, as they can’t be regenerated without data loss. so, raid is mandatory, which is already the case, but what about backup? how can i achieve a backup/snapshot of both, the mdbox (nfs share) and the index files (local raid) and assure they are consistent? greetings...

7 9

Unseen field reported by imap status command returns wrong count for shared mailboxes on dovecot cluster
by Nikolaos Pyrgiotis 19 Oct '22

19 Oct '22

Hello, We recently migrated our mail server to a dovecot cluster of 5nodes, a dovecot proxy, 2directors and 2dovecot backends. All dovecot nodes run version 2.19.1. We use a glusterfs mounted volume on the backends forthe mail storage. We noticed that when issuing the IMAP command to check forUNSEEN messages formails on the shared namespace instead of seeing the value of the unseen messages of the user that the mailbox has been shared to, the value of the unseen messages of the owner of the mailbox is returned. This behavior causes thunderbird when getting new messages forshared mailboxes, to show briefly all messages of the mailbox as unseen forthe user before showing the correct unseen count forthe shared mailbox. The mail location of the shared mailboxes is defined with imapc storage type as described inthe documentation. Is this a dovecot bug? Can we configure a different dovecot configuration setting so that imap status command reports the correct unseen field count when mail location is an imapc storage location? An examples is given below when running doveadm command from one the 2 dovecot directors: When issuing the status command we see that the unseen count is 2: root@doved0-rmt0-cn1:/etc/cron.d# doveadm mailbox status -u npyrgiotis all shared.sysadmins doveadm(npyrgiotis): Info: remote(10.101.0.71:8080): doveadm(npyrgiotis(a)domie02.com)<19078><9l8IJTb+GWOGSgAAEU9A+w>: imapc(10.101.0.75:143): Connected to 10.101.0.75:143 (local 10.101.0.71:33476) shared.sysadmins messages=2 recent=0 uidnext=3 uidvalidity=1662640492 unseen=2 highestmodseq=3 vsize=3950 guid=c92f64f79f0d1ed01e6d5b314f04886c firstsaved=1662643853 shared.sysadmins messages=2recent=0uidnext=3uidvalidity=1662640492unseen=2highestmodseq=3vsize=3950guid=c92f64f79f0d1ed01e6d5b314f04886c firstsaved=1662643853 But when fetching the emails of the mailboxes we can see that the \Seen flag is set for both emails root@doved0-rmt0-cn1:/etc/cron.d# doveadm fetch -u npyrgiotis flags mailbox shared.sysadmins ALL doveadm(npyrgiotis): Info: remote(10.101.0.71:8080): doveadm(npyrgiotis(a)domie02.com)<19074><e7rWDgj+GWOCSgAAEU9A+w>: imapc(10.101.0.75:143): Connected to 10.101.0.75:143 (local 10.101.0.71:38750) flags: \Seen flags: \Seen Below i post the dovecot configuration of one of the two dovecot backends: # 2.3.19.1 (9b53102964): /etc/dovecot/dovecot.conf # Pigeonhole version 0.5.19 (4eae2f79) # OS: Linux 5.10.0-17-amd64 x86_64 Debian 11.4 # Hostname: doveb0-rmt0-cn1 auth_cache_negative_ttl = 5mins auth_cache_size = 50M auth_debug = yes auth_default_realm = example.com auth_master_user_separator = * auth_mechanisms = plain login auth_verbose = yes auth_worker_max_count = 16 disable_plaintext_auth = no first_valid_uid = 499 hostname = smtp.example.com imapc_features = fetch-bodystructure fetch-headers rfc822.size search modseq acl delay-login imapc_host = 10.101.0.75 imapc_password = # hidden, use -P to show it imapc_sasl_mechanisms = plain login imapc_ssl = starttls imapc_ssl_verify = no last_valid_uid = 499 lda_mailbox_autocreate = yes lda_mailbox_autosubscribe = yes login_greeting = You have successfully logged into example.com IMAP server login_trusted_networks = 10.101.0.73 10.101.0.74 mail_always_cache_fields = flags hdr.* date.received date.sent mail_cache_fields = flags date.received guid size.physical size.virtual imap.bodystructure body.snippet mail_debug = yes mail_fsync = always mail_plugins = " notify mail_log zlib acl" mail_privileged_group = mail 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 mdbox_rotate_size = 200M mmap_disable = yes namespace example { list = children location = imapc:~/shared/%%n:INDEXPVT=~/shared-pvt/%%n prefix = shared.%%n. separator = . subscriptions = no type = shared } 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 Spam.Virus { auto = subscribe } mailbox Spam { auto = subscribe } mailbox Trash { special_use = \Trash } prefix = separator = . subscriptions = yes type = private } passdb { args = password=#hidden_use-P_to_show# driver = static master = yes override_fields = allow_real_nets=127.0.0.0/8,local,10.101.0.73,10.101.0.74 userdb_acl_user=%{auth_user} userdb_namespace/example/disabled=yes result_success = continue } passdb { args = password=#hidden_use-P_to_show# driver = static override_fields = allow_real_nets=127.0.0.0/8,local,10.101.0.73,10.101.0.74 result_success = continue } passdb { args = /etc/dovecot/dovecot-ldap-users.conf.ext driver = ldap } passdb { args = /etc/dovecot/dovecot-ldap-groups.conf.ext driver = ldap } plugin { acl = vfile:/etc/dovecot/global-acls/%d/master-dovecot-acl:cache_secs=300 acl_defaults_from_inbox = yes acl_globals_only = no acl_shared_dict = file:/var/dovecot-acl/%d/shared-mailboxes.db imap_compress_deflate_level = 6 mail_log_events = flag_change mail_log_fields = uid box flags sieve = file:~/sieve;active=~/sieve/%n.sieve sieve_before = /var/vmail/global-sieve/global.sieve sieve_env_email_address = %u sieve_env_mailbox_prefix = %{userdb:mailbox_prefix} sieve_global = /var/vmail/sieve sieve_global_extensions = +editheader +vnd.dovecot.environment zlib_save = zstd zlib_save_level = 5 } protocols = " imap lmtp sieve submission" service auth-worker { user = dovecot } service auth { unix_listener auth-userdb { group = mail mode = 0666 user = vmail } } service doveadm { inet_listener dovadm-dom-mgmt { address = 10.100.1.71 port = 8080 ssl = no } inet_listener dovadm-dom { address = 10.101.0.71 port = 8080 ssl = no } vsz_limit = 256M } service imap-login { inet_listener imap-dom { address = 10.101.0.71 port = 143 ssl = no } inet_listener imap { port = 0 } inet_listener imaps-dom { address = 10.101.0.71 port = 993 ssl = yes } inet_listener imaps { port = 0 } process_limit = 400 process_min_avail = 2 service_count = 20 vsz_limit = 512M } service imap { process_limit = 2048 process_min_avail = 0 service_count = 1 vsz_limit = 4G } service lmtp { inet_listener lmtp-dom { address = 10.101.0.71 port = 24 ssl = no } process_limit = 0 process_min_avail = 0 service_count = 0 unix_listener lmtp { mode = 0666 } vsz_limit = 256M } service managesieve-login { inet_listener sieve-dom { address = 10.101.0.71 port = 4190 ssl = no } inet_listener sieve { port = 0 } process_limit = 0 process_min_avail = 0 service_count = 0 vsz_limit = 64M } service managesieve { process_limit = 1024 process_min_avail = 0 service_count = 1 vsz_limit = 256M } service submission-login { inet_listener submission-dom { address = 10.101.0.71 port = 587 ssl = no } inet_listener submission { port = 0 } inet_listener submissions-dom { address = 10.101.0.71 port = 465 ssl = yes } process_limit = 250 process_min_avail = 2 service_count = 1 vsz_limit = 256M } service submission { process_limit = 1024 process_min_avail = 0 service_count = 1 vsz_limit = 256M } ssl = required ssl_cert = </etc/ssl/certs/doveb0-rmt0-cn1.mail.rmt.example.com.pem ssl_client_ca_dir = /etc/ssl/certs ssl_key = # hidden, use -P to show it submission_max_mail_size = 30000k submission_relay_host = 10.101.0.7 submission_relay_port = 587 submission_relay_ssl = starttls submission_relay_ssl_verify = no submission_relay_trusted = yes userdb { driver = prefetch } userdb { args = /etc/dovecot/dovecot-ldap-users.conf.ext driver = ldap } userdb { args = /etc/dovecot/dovecot-ldap-groups.conf.ext driver = ldap } protocol lmtp { mail_plugins = " notify mail_log zlib acl sieve acl" } protocol lda { mail_plugins = " notify mail_log zlib acl sieve acl" } protocol imap { mail_max_userip_connections = 100 mail_plugins = " notify mail_log zlib acl" } protocol sieve { mail_max_userip_connections = 40 } protocol submission { mail_max_userip_connections = 70 } local10.101.0.71 { doveadm_allowed_commands = doveadm_password = # hidden, use -P to show it } local10.100.1.71 { doveadm_allowed_commands = doveadm_password = # hidden, use -P to show it } Thank you, Nikolaos Pyrgiotis

2 3

is it possible to add a custom special use mailbox
by Marc 18 Oct '22

18 Oct '22

Currently I am using this to try and catch everything in Sent. mailbox Sent { special_use = \Sent auto = create } mailbox "Sent Items" { special_use = \Sent auto = no } mailbox "Sent Messages" { special_use = \Sent auto = no } I would like to have something mailbox Test { special_use = \Test auto = create } mailbox "Test Items" { special_use = \Test auto = no } mailbox "testing" { special_use = \Test auto = no }

1 1

Dovecot mail-crypt webmail can't read encrypted messages
by Serveria Support 18 Oct '22

18 Oct '22

I'm trying to setup Dovecot with mail-crypt plugin with per-user encryption. I have configured mail-crypt plugin as per official guide here: https://doc.dovecot.org/configuration_manual/mail_crypt_plugin/ After that I created a user and an encrypted key by running this command: doveadm -o \plugin/mail_crypt_private_password=12345 mailbox cryptokey generate -u mail(a)example.org -URf (replacing dummy data ofc) I can log in to webmail (and Dovecot) just fine, emails are getting sent and delivered. I have also checked the storage and the messages seem to be stored encrypted. However, I can't read the emails in webmail (just headers can be seen) and in Dovecot logs I can see the following error: failed: Private key not available: Cannot decrypt key ### Cannot decrypt key ### <8632: Password not available (FETCH RFC822.HEADER) There seems to be an issue with mySQL query. The query I'm using (Select username as "user", password,"%w" as userdb_mail_crypt_private_password from mailbox;) seems to work just fine, when run from mysql prompt it outputs the usernames and passwords, but the error is still there (Cannot decrypt key ### Password not available). Any ideas? What am I missing?

16 70

sieve script not modifying header
by Marc 17 Oct '22

17 Oct '22

From the command line the sieve script is modifying the header like this: su testuser -s '/bin/bash' -c 'cat test.msg | /usr/lib64/dovecot/sieve-execute/sieve-test' However when executing via dovecot, the header stays unchanged require ["copy","fileinto","vacation","vnd.dovecot.execute","editheader"]; # rule:[testing2] if not execute :pipe "sieve-test" { } Any idea what I am forgetting to configure/allow?

1 1