June 2019 - dovecot - dovecot.org

IMAP copy stopped copying flags
by Andrzej A. Filip 29 Jul '19

29 Jul '19

Is it intended behavior? It seems to be caused by upgrade to 1:2.3.2-2 on Debian/Testing. -- A. Filip

4 6

Re: Best mail encryption solution for per-user
by Aki Tuomi 12 Jul '19

12 Jul '19

On 27.05.2018 21:16, mail(a)sjemm.net wrote: > May 27, 2018 8:52 AM, "Aki Tuomi" <aki.tuomi(a)dovecot.fi> wrote: >>> On 26 May 2018 at 10:36 mail(a)sjemm.net wrote: >>> >>> May 23, 2018 10:10 AM, mail(a)sjemm.net wrote: >>> May 23, 2018 9:46 AM, "Aki Tuomi" <aki.tuomi(a)dovecot.fi> wrote: >>> >>> On 23.05.2018 10:15, mail(a)sjemm.net wrote: >>> >>> May 23, 2018 8:31 AM, "Aki Tuomi" <aki.tuomi(a)dovecot.fi> wrote: >>> >>> On 23.05.2018 09:13, mail(a)sjemm.net wrote: >>> May 20, 2018 8:01 PM, mail(a)sjemm.net wrote: >>> May 20, 2018 2:47 PM, "Aki Tuomi" <aki.tuomi(a)dovecot.fi> wrote: >>> On 19 May 2018 at 16:40 mail(a)sjemm.net wrote: >>> >>> May 18, 2018 10:01 PM, "Aki Tuomi" <aki.tuomi(a)dovecot.fi> wrote: >>> On 18 May 2018 at 21:44 mail(a)sjemm.net wrote: >>> >>> May 18, 2018 4:43 PM, "Aki Tuomi" <aki.tuomi(a)dovecot.fi> wrote: >>> On 18 May 2018 at 17:38 mail(a)sjemm.net wrote: >>> >>> May 18, 2018 4:05 PM, "Aki Tuomi" <aki.tuomi(a)dovecot.fi> wrote: >>> On 18 May 2018 at 16:43 mail(a)sjemm.net wrote: >>> >>> Hi Tai74 and Aki, >>> I followed your conversation with interest on how to setup per user encryption in dovecot. >>> I have setup my dovecot with the following in a conf file: >>> >>> ============== >>> >>> mail_attribute_dict = file:%h/Maildir/dovecot-attributes >>> mail_plugins = $mail_plugins mail_crypt >>> plugin { >>> >>> mail_crypt_curve = secp521r1 >>> >>> mail_crypt_save_version = 2 >>> >>> } >>> >>> ============== >>> >>> This works nice, all emails are being encrypted and every user/folder has keys. >>> But as I understood from your conversation these keys are not protected. And I want them to be >>> protected by the users password used by imap. >>> >>> Those passwords are stored in a mysql DB file. ( I used a guide from workaround [dot] org to set up >>> the DB and postfix/dovecot) >>> >>> but how would i set it so, that the users password from the DB is used to encrypt the keys? >>> >>> should i use mail_crypt_private_password = ? >>> how do i point it to the mysql db then? >>> im unsure about this >>> >>> Do you have any hints on this? >>> >>> Kind regards, >>> Zjemm >>> >>> The passwords in your MySQL database are, hopefully, not in plaintext. If you want to secure your >>> user's keys using user's login password, you must have a TOOL that manages this. >>> >>> You can use mail_crypt_private_password = %w in (mysql) passdb fields to provide the user's login >>> password as private password. You might want to run it thru some hash, so %{sha1:password} might be >>> a good option. >>> >>> You can change the key password using 'doveadm mailbox cryptokey', this needs to be done every time >>> user changes his password. >>> >>> Also note that if you go down this road, and the user forgets his password, you will not be able to >>> recover the emails without backup copy of the private key. >>> >>> Aki >>> >>> Hi Aki >>> >>> I used the following command: >>> dovecot pw -s SHA256-CRYPT >>> >>> the output on the chosen password looks like: {SHA256-CRYPT}$5$Rokc06a7In4SF3bO$OQpGQWqg........ >>> >>> This output is used to store in the password fields in the database. So no plain text passwords no >>> :) >>> >>> You can use mail_crypt_private_password = %w in (mysql) passdb fields to provide the user's login >>> password as private password. >>> >>> can you explain this a bit more for me? >>> >>> for now i have in the 10-auth.conf file the following: >>> ============== >>> passdb { >>> driver = sql >>> >>> # Path for SQL configuration file, see example-config/dovecot-sql.conf.ext >>> args = /etc/dovecot/dovecot-sql.conf.ext >>> } >>> >>> and: >>> >>> userdb { >>> driver = static >>> args = uid=vmail gid=vmail home=/var/vmail/%d/%n >>> } >>> ============== >>> >>> then i have in dovecot-sql.conf.ext >>> ============== >>> driver = mysql >>> connect = host=x.x.x.x dbname=mailserver user=mailuser password=mailpasswordexample >>> default_pass_scheme = SHA256-CRYPT >>> password_query = SELECT email as user, password FROM virtual_users WHERE email='%u'; >>> ============== >>> Where do i need to set : mail_crypt_private_password = %w ? >>> >>> password as private password. You might want to run it thru some hash, so %{sha1:password} might be >>> a good option. >>> >>> the passwords are allready hashed in the DB using: dovecot pw -s SHA256-CRYPT to genereate the has. >>> so this step isnt nesesary anymore am i right? >>> >>> Thank you for your quick response, very helpfull >>> >>> Zjemm >>> >>> You misunderstood a bit. The idea is to use the *plaintext* password as the password for the >>> private key. Otherwise anyone could just decrypt it by looking at your database where the hashed >>> password is.. >>> >>> So: >>> >>> password_query = SELECT email as user, password, '%w' AS userdb_mail_crypt_private_password FROM >>> virtual_users WHERE email='%u' >>> >>> Aki >>> >>> Hi Aki, >>> >>> Thank you very much for your help, i realy appreciate that. >>> >>> Ok so if i understand it correctly i'll have to use: >>> >>> password_query = SELECT email as user, password, '%w' AS userdb_mail_crypt_private_password FROM >>> virtual_users WHERE email='%u' >>> >>> in my dovecot-sql.conf.ext file >>> >>> This query selects the user, the password, and %w >>> >>> if i run a little query myself: >>> MariaDB [mailserver]> SELECT email as user, password, '%w' AS userdb_mail_crypt_private_password >>> FROM virtual_users; >>> +------------------+----------------------------------+------------------------------------+ >>> | user | password | userdb_mail_crypt_private_password | >>> +------------------+----------------------------------+------------------------------------+ >>> | john(a)example.org | {SHA256-CRYPT}$5$M/GWzmtjsLroRWI | %w | >>> +------------------+----------------------------------+------------------------------------+ >>> >>> %w is a dovecot variable, and stands for the plaintext password, but the password is not stored as >>> plaintext in the DB, %w get filled with the actual plaintext password by dovecot upon the user that >>> is typing in the password when authenticating. >>> >>> is this correct? >>> >>> yes. >>> >>> so then i have the username the hashed password en the plaintext password as a result of the query. >>> >>> yes >>> >>> now userdb_mail_crypt_private_password = the plaintext password >>> do i need to reference it somewhere? or is userdb_mail_crypt_private_password autmatically used by >>> the dovecot mail_crypt plugin to encrypt the keys? or should it be mail_crypt_private_password? >>> >>> It gets injected into the mail process as 'mail_crypt_private_password', as if it was set in plugin >>> {} section. >>> >>> if i have this setup working i'm going to write a blog post on this topic to share this knowledge >>> >>> Thanks again and have a great weekend. >>> >>> Zjemm >>> >>> Aki >>> >>> Hi Aki, >>> >>> Cool i'm testing it right now. >>> I have set up a new mailserver (life is great with lxc containers :) ) >>> >>> postfix and dovecot are working like normal >>> >>> next i enable mail_crypt >>> >>> i did create a file: /etc/dovecot/conf.d/10-mailcrypt.conf >>> ========================== >>> mail_attribute_dict = file:%h/Maildir/dovecot-attributes >>> >>> mail_plugins = $mail_plugins mail_crypt >>> >>> plugin { >>> mail_crypt_curve = secp521r1 >>> mail_crypt_save_version = 2 >>> } >>> ========================== >>> >>> and then i changed the file: /etc/dovecot/dovecot-sql.conf.ext >>> >>> so the query is now the new query: >>> password_query = SELECT email as user, password, '%w' AS userdb_mail_crypt_private_password FROM >>> virtual_users WHERE email='%u'; >>> >>> then i restarted dovecot and postfix and send a test email to the one and only testuser that is in >>> there. >>> >>> when i open the mailbox with the tool mutt, i can see the new email, and when openening the email >>> the mutt client drops the connection. >>> >>> in the log i can see: >>> >>> May 19 13:34:48 mailserver1.example.local dovecot[600]: imap-login: Login: user=<john(a)example.org>, >>> method=PLAIN, rip=::1, lip=::1, mpid=713, TLS, session=<E3PnIY9sNM4AAAAAAAAAAAAAAAAAAAAB> >>> May 19 13:34:49 mailserver1.example.local dovecot[600]: imap(john(a)example.org): Error: read() >>> failed: >>> read(/var/vmail/example.org/john/Maildir/cur/1526736378.M161472P641.mailser…, >>> =571:2,) failed: Private key not available: Cannot decrypt key >>> bfc5bb25b1bf64290eea6dc14b516c6a0a25b64551b6e4f0f8677ba7274887cb: error:03070068:bignum >>> routines:BN_mpi2bn:encoding error (FETCH BODY[] for mailbox INBOX UID 8) >>> >>> i think i missed a step, but witch one? >>> >>> the userpassword hasnt been changed (that would be the next step in the testing process) >>> >>> should i've use doveadm first to encrypt the key with that userpassword? i thought it would do that >>> on the fly, because the initial keys where only just created when enabling the mail_crypt plugin >>> >>> please let me know your thougts >>> Zjemm >>> I noticed you replied directly to me, and not to the list, too... fixed that for you. >>> >>> mail_crypt_private_password is used when key is created, but if you have created it before using >>> password, you'll need to encrypt it before turning the setting on. >>> >>> Aki >>> Hi, Ok i'm sorry about that, thank you for fixing that. i'm a bit new to mailing lists :) >>> >>> are you a dovecot devoloper? or a enthusiastic user? >>> >>> anyway, i managed to get it working now with all your help :) >>> >>> to start fresh i did a: >>> rm -rf /var/vmail/example.org >>> >>> so all email is gone, and i assume all dovecot keys are gone that way. >>> >>> Then i tried to set a password first: >>> >>> root@mailserver1:/var/vmail# doveadm mailbox cryptokey password -u john(a)example.org -n summersun >>> result: Changed password for 0 key(s) >>> >>> (summersun = the password for this user) >>> >>> but then it says there are 0 keys, so then i send the test user an email and try to open the >>> mailbox, i'll get: >>> >>> imap(john(a)example.org): Error: read() failed: >>> read(/var/vmail/example.org/john/Maildir/cur/1526827992.M149712P883.mailser…, >>> =561:2,) failed: Private key not available: Cannot decrypt key >>> 71849013a70b0c631c06112077e7c2fe39b0b2737b4933b219793841209d4e7f: error:03070068:bignum >>> routines:BN_mpi2bn:encoding error >>> >>> but hey, now the key's are created, so i tried to set the password again: >>> >>> root@mailserver1:/var/vmail# doveadm mailbox cryptokey password -u john(a)example.org -n summersun >>> result: dcrypt_key_load_private(787701bd677dd69a26842547a3926cbaa625b0b5a91751f06678c3e9708343d9) >>> failed: password missing >>> ========= >>> >>> Lets start over again, i did a new: >>> rm -rf /var/vmail/example.org >>> >>> i disabled the mail_crypt_private_password in the sql query and send an email to the test user. >>> now again new keys are generated. >>> >>> then i did set the password via doveadm: >>> >>> root@mailserver1:/var/vmail# doveadm mailbox cryptokey password -u john(a)example.org -n summersun >>> result: Changed password for 1 key(s) >>> >>> i enabled the mail_crypt_private_password again in the sql query part and now it works :) >>> >>> YESSS!!! >>> >>> if i now change the password for the user, i cannot read the email anymore. that is what should >>> happen. >>> so now i changed the password for this user also with doveadm: >>> - doveadm mailbox cryptokey password -u john(a)example.org -n qwerty -o summersun >>> >>> and now i'm able to read the emails again. so it all works now as expected. >>> >>> i have now only one thing remaining. >>> >>> when i want to add a new user, i have to somehow: >>> - create the new user in the mysql DB >>> - start with dovecot not using mail_crypt_private_password (so disabled) >>> - send an initial email to let the users mailbox be created and generate the keys >>> - set the users password with doveadm >>> - restart dovecot again with mail_crypt_private_password (so enabled) >>> >>> but this would be disruptive to existing users, and i would have to script the whole thing as a >>> "add-new-user" script to make it usable i guess. >>> >>> do you know of a more easy way of acomplishing this? >>> could i use doveadm for all steps, and get around the mail_crypt_private_password disable part? >>> >>> or could i add a column in the mysql db called userdb_mail_crypt_private_password and fill that >>> column with %w for users that allready exist, and empty for new users. >>> when being empty, it might not set the mail_crypt_private_password for new users >>> >>> or is this the wrong way of thinking? >>> >>> let me know your thoughts on this. >>> >>> And last but not least, i really want to thank you for all your help. It is a really nice >>> experience. >>> Bless you! >>> >>> Zjemm >>> Hi Aki, >>> >>> You did fix the posting on the mail archive, i can see our conversation on there, all but the last >>> email i send to you. >>> Maybe you did not received the last email? >>> >>> would you be willing to take a look at my last question in the email See below: >>> Thank you very much. >>> >>> ================================ >>> i have now only one thing remaining. >>> >>> when i want to add a new user, i have to somehow: >>> - create the new user in the mysql DB >>> - start with dovecot not using mail_crypt_private_password (so disabled) >>> - send an initial email to let the users mailbox be created and generate the keys >>> - set the users password with doveadm >>> - restart dovecot again with mail_crypt_private_password (so enabled) >>> >>> but this would be disruptive to existing users, and i would have to script the whole thing as a >>> "add-new-user" script to make it usable i guess. >>> >>> do you know of a more easy way of acomplishing this? >>> could i use doveadm for all steps, and get around the mail_crypt_private_password disable part? >>> >>> or could i add a column in the mysql db called userdb_mail_crypt_private_password and fill that >>> column with %w for users that allready exist, and empty for new users. >>> when being empty, it might not set the mail_crypt_private_password for new users >>> >>> or is this the wrong way of thinking? >>> >>> let me know your thoughts on this. >>> >>> And last but not least, i really want to thank you for all your help. It is a really nice >>> experience. >>> Bless you! >>> >>> Zjemm >>> >>> If you have mail_crypt_private_password set *when* keys are generated, >>> dovecot should use that password to encrypt the user key. >>> >>> Aki >>> Hi Aki, >>> >>> well, if there is a new email user setup in the mysql DB, and no email has been send to that new >>> user. at that point there are no keys. >>> >>> So trying to set a password on those key's wont work. see: >>> root@mailserver1:/var/vmail/example.org# doveadm mailbox cryptokey password -u john2(a)example.org -n >>> qwerty >>> result: Changed password for 0 key(s) >>> >>> the keys need to be generated first. And that only happens when sending a mail to that new user. >>> Also, at the point of creating the keys, the mail_crypt_private_password should be disabled >>> otherwise the keys are generated and also encrypted with no user password, and then im unable to >>> set a new pasword for that key >>> >>> How can i set the password before the keys are generated? >>> or can i manually generate key's and then set the password? >>> >>> so at this point i have to do the following: >>> >>> You can use doveadm mailbox cryptokey generate -u user -U >>> >>> to generate a user key. >>> >>> Aki >>> >>> - create the new user in the mysql DB >>> - start with dovecot not using mail_crypt_private_password (so disabled) >>> - send an initial email to let the users mailbox be created and generate the keys >>> - set the users password with doveadm >>> - restart dovecot again with mail_crypt_private_password (so enabled) >>> can i somehow enable the mail_crypt_private_password per user? >>> because this mysql query always returns: %w >>> and thus allways sets: userdb_mail_crypt_private_password >>> SELECT email as user, password, '%w' AS userdb_mail_crypt_private_password FROM virtual_users; >>> >>> Hi Aki, >>> >>> You are correct >>> >>> doveadm mailbox cryptokey generate -u user -U generates the keys, but i have to first remove: >>> '%w' AS userdb_mail_crypt_private_password >>> from dovecot configuration and restart dovecot. >>> >>> if i don't do that, the keys are generated, but also somehow encrypted using: no >>> password/empty/something else (i don't know) >>> >>> here you can see that happening: >>> >>> root@mailserver1:/var/vmail/example.org# doveadm mailbox cryptokey generate -u john2(a)example.org -U >>> Folder Public ID >>> ✓ <userkey> 53004acf9886f887ca081c83d7392a5aa3fac4b5a20ce013db91a341fb4644c4 >>> root@mailserver1:/var/vmail/example.org# doveadm mailbox cryptokey password -u john2(a)example.org -n >>> qwerty >>> result: dcrypt_key_load_private(53004acf9886f887ca081c83d7392a5aa3fac4b5a20ce013db91a341fb4644c4) >>> failed: password missing >>> >>> it expects an old password wich is never set in my opinion. >>> >>> so the last part of this setup would be to figure out a way to disable '%w' AS >>> userdb_mail_crypt_private_password for new users without manually removing that part from the query >>> and restarting dovecot. As that would mean connection interruption while adding new users >>> >>> if we could add new users to the DB and somehow not give '%w' AS userdb_mail_crypt_private_password >>> for that new user in the query, we can add the password afterward, and then enable '%w' AS >>> userdb_mail_crypt_private_password in the query for this user >>> >>> could we add a column in the user db lets say called: encrypted (yes/no) >>> >>> and then change the existing query: SELECT email as user, password, '%w' AS >>> userdb_mail_crypt_private_password FROM virtual_users; >>> >>> to firrt check if encryption is set to 'yes', if so retrun: >>> SELECT email as user, password, '%w' AS userdb_mail_crypt_private_password FROM virtual_users; >>> >>> if not return: >>> SELECT email as user, password FROM virtual_users; >>> >>> but then in one mysql query so dovecot can work with it >>> >>> ? >>> >>> Hi Aki, >>> >>> would you be willing to respond to my last question i had send to you last week? >>> its this one: >>> ================================== >>> doveadm mailbox cryptokey generate -u user -U generates the keys, but i have to first remove: >>> '%w' AS userdb_mail_crypt_private_password >>> from dovecot configuration and restart dovecot. >>> >>> if i don't do that, the keys are generated, but also somehow encrypted using: no >>> password/empty/something else (i don't know) >>> >>> here you can see that happening: >>> >>> root@mailserver1:/var/vmail/example.org# doveadm mailbox cryptokey generate -u john2(a)example.org -U >>> Folder Public ID >>> ✓ <userkey> 53004acf9886f887ca081c83d7392a5aa3fac4b5a20ce013db91a341fb4644c4 >>> root@mailserver1:/var/vmail/example.org# doveadm mailbox cryptokey password -u john2(a)example.org -n >>> qwerty >>> result: dcrypt_key_load_private(53004acf9886f887ca081c83d7392a5aa3fac4b5a20ce013db91a341fb4644c4) >>> failed: password missing >>> >>> it expects an old password wich is never set in my opinion. >>> >>> could this be a bug? or am i doing it wrong? if needed i could send in a bug report? >>> >>> or might we need to enable the userdb_mail_crypt_private_password "per user" ? >>> >>> so the last part of this setup would be to figure out a way to disable '%w' AS >>> userdb_mail_crypt_private_password for new users without manually removing that part from the query >>> and restarting dovecot. As that would mean connection interruption while adding new users >>> >>> if we could add new users to the DB and somehow not give '%w' AS userdb_mail_crypt_private_password >>> for that new user in the query, we can add the password afterward, and then enable '%w' AS >>> userdb_mail_crypt_private_password in the query for this user >>> >>> could we add a column in the user db lets say called: encrypted (yes/no) >>> >>> and then change the existing query: SELECT email as user, password, '%w' AS >>> userdb_mail_crypt_private_password FROM virtual_users; >>> >>> to firrt check if encryption is set to 'yes', if so retrun: >>> SELECT email as user, password, '%w' AS userdb_mail_crypt_private_password FROM virtual_users; >>> >>> if not return: >>> SELECT email as user, password FROM virtual_users; >>> >>> but then in one mysql query so dovecot can work with it >>> >>> Please let me know your thougts, after this last thing im done :) >>> also let me know if i can support this project in some way, im willing to contribute >>> >>> Zjemm >> You can select it as userdb_mail_crypt_save_version=0 to disable encryption (it won't disable >> decryption). You can use value '2' for enabling encryption. DO NOT USE 1. >> >> Also I tried the SQL based thing, and if you had EMPTY mail_crypt_private_password, try these to >> change the password. If the one that works is the second one, let me know =) >> >> doveadm mailbox cryptokey password -u testuser -nnewpass -o "" >> >> doveadm mailbox cryptokey password -u testuser -nnewpass -o "yes" >> >> Aki > Hi Aki, > > Thanks for replying > > So if i understand you correctly i could enable encryption per user by using: userdb_mail_crypt_save_version= in the database as an extra column. the column would be called "userdb_mail_crypt_save_version" and the value is "0" or "2" > > if a user has: userdb_mail_crypt_save_version=0, encryption is disabled for that user > if a user has: userdb_mail_crypt_save_version=2, encryption is enabled for that user > > would this also override the setting: mail_crypt_save_version = 2 > in the mailcryp.conf file where that is a global setting? or should i delete it there and only use userdb_mail_crypt_save_version= from the database? > > for the password set command i hve testest some things: > > new user with no keys yet: > doveadm -o plugin/mail_crypt_private_password=password mailbox cryptokey generate -u john2(a)example.org -U > > i can set a password with: > new password: > doveadm mailbox cryptokey password -u john2(a)example.org -n newpass -o password > > > if i do not use new user doveadm: (doveadm -o plugin/mail_crypt_private_password=password mailbox cryptokey generate -u john2(a)example.org -U) > then use this: > doveadm mailbox cryptokey password -u john2(a)example.org -n newpass -o "yes" > > > so yes it is the second one > > Kind regards, > > Zjemm It's unfortunate problem with 2.2 that it defaults empty userdb variables into yes. This has been remedied in 2.3. Unfortunately there is no clean fix to this, they all resort to various levels of trickery. Variables set in passdb/userdb overwrite the ones in plugin {} section. Aki

2 2

Frequent Out of Memory for service(config)
by Root Kev 12 Jul '19

12 Jul '19

Hello Group, We have dovecot deployed as solely a Pop3 service that is used by our applications to pass mail from one application to another internally. We have roughly 4 applications that connect to the Pop3 service every 2 seconds, to check for new messages and pop them for processing if they are present. Depending on the site, we have between 1024-2048MB of memory set for default_vsz_limit. In all systems we see the Out of memory alert several times a day. We previously did not see this at all when running on CentOS6, with less memory. We have tried increasing the memory to the vsz_limit up to 2gb without success. We are running on CentOS 7 servers, running dovecot 2.3.6 (7eab80676) (from the dovecot repo). Can anyone advise any other settings that could be modified in order to correct these out of memory issues? # dovecot -n # 2.3.6 (7eab80676): /etc/dovecot/dovecot.conf # OS: Linux 3.10.0-957.5.1.el7.x86_64 x86_64 CentOS Linux release 7.6.1810 (Core) # Hostname: ****** #<modified for security> auth_cache_size = 10 M auth_verbose = yes default_vsz_limit = 1 G instance_name = Pop3 Mail Service listen = 10.*.*.* #<modified for security> log_path = /var/log/dovecot.log login_greeting = Pop3 Mail Service login_trusted_networks = 10.*.*.* 10.*.*.* 10.*.*.* 10.*.*.* 10.*.*.* #<modified for security> mail_location = maildir:~/Maildir 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 { args = cache_key=#hidden_use-P_to_show# driver = pam } protocols = pop3 ssl_cert = </etc/pki/dovecot/certs/dovecot.pem ssl_key = # hidden, use -P to show it userdb { driver = passwd } verbose_ssl = yes May 10 06:44:05 config: Fatal: pool_system_malloc(8192): Out of memory May 10 06:44:05 config: Fatal: master: service(config): child 27887 returned error 83 (Out of memory (service config { vsz_limit=1024 MB }, you may need to increase it) - set CORE_OUTOFMEM=1 environment to get core dump) May 10 14:56:31 config: Fatal: pool_system_malloc(8192): Out of memory May 10 14:56:31 config: Fatal: master: service(config): child 2495 returned error 83 (Out of memory (service config { vsz_limit=1024 MB }, you may need to increase it) - set CORE_OUTOFMEM=1 environment to get core dump) May 10 23:09:02 config: Fatal: pool_system_malloc(8192): Out of memory May 10 23:09:02 config: Fatal: master: service(config): child 10581 returned error 83 (Out of memory (service config { vsz_limit=1024 MB }, you may need to increase it) - set CORE_OUTOFMEM=1 environment to get core dump) May 11 10:18:43 config: Fatal: pool_system_malloc(8192): Out of memory May 11 10:18:43 config: Fatal: master: service(config): child 30511 returned error 83 (Out of memory (service config { vsz_limit=1024 MB }, you may need to increase it) - set CORE_OUTOFMEM=1 environment to get core dump) May 11 18:30:59 config: Fatal: pool_system_malloc(1608): Out of memory May 11 18:30:59 config: Fatal: master: service(config): child 12134 returned error 83 (Out of memory (service config { vsz_limit=1024 MB }, you may need to increase it) - set CORE_OUTOFMEM=1 environment to get core dump) May 12 02:57:28 config: Fatal: pool_system_malloc(8192): Out of memory May 12 02:57:28 config: Fatal: master: service(config): child 24940 returned error 83 (Out of memory (service config { vsz_limit=1024 MB }, you may need to increase it) - set CORE_OUTOFMEM=1 environment to get core dump) May 12 11:07:34 config: Fatal: pool_system_malloc(8192): Out of memory May 12 11:07:35 config: Fatal: master: service(config): child 8203 returned error 83 (Out of memory (service config { vsz_limit=1024 MB }, you may need to increase it) - set CORE_OUTOFMEM=1 environment to get core dump) May 12 19:17:52 config: Fatal: pool_system_malloc(8192): Out of memory May 12 19:17:52 config: Fatal: master: service(config): child 14623 returned error 83 (Out of memory (service config { vsz_limit=1024 MB }, you may need to increase it) - set CORE_OUTOFMEM=1 environment to get core dump) May 13 03:26:34 config: Fatal: pool_system_malloc(8192): Out of memory May 13 03:26:35 config: Fatal: master: service(config): child 21479 returned error 83 (Out of memory (service config { vsz_limit=1024 MB }, you may need to increase it) - set CORE_OUTOFMEM=1 environment to get core dump) May 13 11:35:42 config: Fatal: pool_system_malloc(8192): Out of memory May 13 11:35:43 config: Fatal: master: service(config): child 26900 returned error 83 (Out of memory (service config { vsz_limit=1024 MB }, you may need to increase it) - set CORE_OUTOFMEM=1 environment to get core dump) May 13 19:34:26 config: Fatal: pool_system_malloc(8192): Out of memory May 13 19:34:26 config: Fatal: master: service(config): child 32187 returned error 83 (Out of memory (service config { vsz_limit=1024 MB }, you may need to increase it) - set CORE_OUTOFMEM=1 environment to get core dump). Thanks, Kevin

4 6

Dovecot behind Load Balancer
by Paolo Daniele 10 Jul '19

10 Jul '19

Hi, i've a question for you. I've two dovecot imap/pop server behind a zen load balancer. Load balancing is made by lx4nat so the public ip address of my load balancer contact directly the dovecot servers. Since few months i've a message from thunderbird that i've reached the imap limit login for ip. I've triend to increase the max user ip parameter but sometimes i've the same problem. It's a strange things that actually i'm able to mitigate by reduce the number of cached connections in Thunderbird but it's not normal. What do you think about that? Maybe there's some tuning that you can suggest. Thank you, Paolo

5 10

Applying Dovecot for a large / deep folder-hierarchy archive.
by Arnold Opio Oree 10 Jul '19

10 Jul '19

Hello to you all, I'd like to ask about my intended application of Dovecot to create a folder-hierarchy for storing our enterprise emails, which are treated as live data rather than archives for compliance or occasional / reactive retrieval. The data is presently not that large (a few gigabytes), but it is expected to grow rapidly. Up to this stage the data has been containedin a Microsoft Exchange mailbox (2013), and then in an offline PST. The move to the offline PST was by necessity, as the large number offolders, and depth of hierarchy to my best understanding caused the exchange server / outlook / evolution mail clients to begin tomalfunction. To cope with this the archive was broken up and the bulk stored in the offline PST and the most active components stored inonline Exchange mailboxes. I have some understanding of the fs mbox format, and also the mitigations to be made for certain characters / strings. My main concern is whether Dovecot is likely to be able to cope well with a large number of folders / depth of hierarcy. I will really appreciate any help / advice you can give. Best regards, Arnold Opio OreeChief Executive OfficerParallax Digital Technologies arnoldoree(a)parallaxdt.com http://www.parallaxdt.com tel : +44 (0) 333 577 8587fax : +44 (0) 20 8711 2477 Parallax Digital Technologies78A Hatfeild MeadLondonSM4 5PF Parallax Digital Technologies is a trading name of Parallax GlobalLimited. U.K. Co. No. 08836288 The contents of this e-mail are confidential. If you are not theintended recipient you are to delete this e-mail immediately, disregardits contents and disclose them to no other persons.

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Dovecot 2.3.0 TLS
by Hauke Fath 07 Jul '19

07 Jul '19

All, our dovecot installation provides a bundle of intermedia CA certificates using the ssl_ca option. 2.3.0 does not supply the bundle, resulting in various clients either complaining about an unverifiable server cert, or quietly not connecting. The log has Jan 5 17:01:46 Bounce dovecot: imap-login: Disconnected (no auth attempts in 0 secs): user=<>, rip=XXX, lip=YYY, TLS handshaking: SSL_accept() failed: error:14094416:SSL routines:SSL3_READ_BYTES:sslv3 alert certificate unknown: SSL alert number 46, session=<uKK/kAlia+GCUyU5> We fixed the issue by downgrading to 2.2.33.2. Cheerio, hauke -- The ASCII Ribbon Campaign Hauke Fath () No HTML/RTF in email Institut für Nachrichtentechnik /\ No Word docs in email TU Darmstadt Respect for open standards Ruf +49-6151-16-21344

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Repository / builds for Debian "buster"?
by Kostya Vasilyev 07 Jul '19

07 Jul '19

Speaking of repositories... Debian "buster" (future version 10) has for some time been "stage 1 frozen" (if I have the terminology right) and quite usable. Perhaps it's starting to make sense to make a repo / start producing builds? -- Kostya Vasilyev kman(a)fastmail.com

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Dovecot and Solr on the same server or on different
by Götz Reinicke 06 Jul '19

06 Jul '19

Hi. what would you suggest? What are the pros and cons for having dovecot and Solr on the same or different hots? I have about 800 accounts, some millions of mails and about 2 TB of zipped mails. From the recent experiences regarding maintenance I’d prefer different hosts for each. Thanks for suggestions and feedback . Götz

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Dovecot LMTP mixing up users on multi-recipient mail
by Bernhard Schmidt 03 Jul '19

03 Jul '19

Hi, I've upgraded a mailstore from Debian Jessie (aka oldstable) with Dovecot 2.2.13 to Debian Buster (next stable) with Dovecot 2.3.4.1 today. It worked pretty well, except that we're seeing error messages very similar to this old thread https://dovecot.org/pipermail/dovecot/2015-July/101396.html It appears to be happening when a mail with multiple recipients on this message store is getting delivered through lmtp. Jun 27 11:47:36 lxmhs74 dovecot: lmtp(user1)<47683><sGwaD7eQFF1DugAAgkzuhA:18>: Error: open(/var/cache/dovecot/index/n/user2n/.INBOX/dovecot.index.cache) failed: Permission denied (euid=3814520(<unknown>) egid=12(man) missing +x perm: /var/cache/dovecot/index/n/user2, dir owned by 3391995:12 mode=0700) user1 uid is 3814520, user2n uid is 3391995. Dovecot appears to be trying to deliver the message to user1 while using the index directory of user2n. Further configuration: - message store is on NFS - cache directory is on local disk - users are coming from LDAP, one UID per user user_attrs = cn=user,homeDirectory=home,uidNumber=uid,gidNumber=gid - index directory is calculated from the username maildir:~/Maildir:INDEX=/var/cache/dovecot/index/%-1.1n/%n Despite the error messages (which appear dozens of times per delivery attempt) delivery seems to work. Workaround was to set lmtp_destination_recipient_limit = 1 on the postfix in front of the message store. Despite the report linked above being quite old, I can't recall having issues with 2.2.13. === doveconf -n === # OS: Linux 4.19.0-5-amd64 x86_64 Debian 10.0 # Hostname: lxmhs74.srv.lrz.de default_vsz_limit = 512 M deliver_log_format = from=<%e>, size=%p, message-id=<%m>, status=%$ imap_id_log = * imap_id_send = * lda_mailbox_autocreate = yes lda_mailbox_autosubscribe = yes login_greeting = Dovecot ready. login_log_format_elements = user=<%u> method=%m rip=%r lip=%l mpid=%e %c session=<%{session}> cipher=<%k> mail_gid = mstore mail_location = maildir:~/Maildir:INDEX=/var/cache/dovecot/index/%-1.1n/%n mail_plugins = quota listescape mail_uid = mstore 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 mmap_disable = yes 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" { special_use = \Sent } mailbox Trash { auto = subscribe special_use = \Trash } prefix = INBOX. separator = . type = private } passdb { args = /etc/dovecot/dovecot-ldap.conf driver = ldap } plugin { quota = maildir quota_rule = *:storage=1024M quota_rule2 = INBOX.Trash:ignore quota_status_nouser = DUNNO quota_status_overquota = 452 4.2.2 Mailbox is full quota_status_success = DUNNO quota_warning = storage=95%% quota-warning 95 %u quota_warning2 = storage=90%% quota-warning 90 %u sieve = ~/currently-active-script.sieve sieve_dir = ~/sieve } pop3_uidl_format = %v-%u protocols = imap lmtp sieve pop3 quota_full_tempfail = yes service anvil { client_limit = 3000 unix_listener anvil { group = sudo mode = 0660 } } service auth { client_limit = 3000 unix_listener auth-userdb { group = mstore mode = 0660 user = mstore } } service imap-login { client_limit = 1024 inet_listener imap { port = 143 } inet_listener imaps { port = 993 ssl = yes } process_limit = 2500 process_min_avail = 4 service_count = 0 } service imap { process_limit = 8192 } service lmtp { inet_listener lmtp { port = 24 } } service managesieve-login { inet_listener sieve { port = 4190 } inet_listener sieve_deprecated { port = 2000 } service_count = 1 } service managesieve { process_limit = 1024 } service pop3-login { inet_listener pop3 { port = 110 } inet_listener pop3s { port = 995 ssl = yes } } service quota-status { client_limit = 20 executable = quota-status -p postfix inet_listener { port = 12340 } } service quota-warning { executable = script /etc/dovecot/quotawarnmsg.sh unix_listener quota-warning { group = mstore mode = 0660 user = mstore } user = mstore } service stats { process_limit = 8192 } ssl_cert = </etc/dovecot/dovecot.pem ssl_dh = # hidden, use -P to show it ssl_key = # hidden, use -P to show it userdb { driver = prefetch } userdb { args = /etc/dovecot/dovecot-ldap-userdb.conf driver = ldap } verbose_proctitle = yes protocol imap { mail_plugins = quota listescape imap_quota imap_zlib } protocol lda { mail_plugins = quota listescape sieve } protocol lmtp { mail_plugins = quota listescape sieve } remote 127.0.0.1 { disable_plaintext_auth = no } remote ::1 { disable_plaintext_auth = no } === Thanks, Bernhard

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Dovecot/MSQL issue
by Nathan 03 Jul '19

03 Jul '19

Hello, I'm trying to work through an issue that cropped up on a server I've been working on and haven't found a very good workaround. Dovecot is operating in a jailed environment. The configuration in dovecot-sql.conf.ext has been set appropriately with the host=127.0.0.1 (which works from a jailed environment) and when dovecot attempts to auth it appears to perform a reverse dns lookup and overwrites the host with the result localhost before using the msql credentials 'user'@'localhost' which then fails after timing out. I'm currently running version 2.2.33.2 of dovecot. The workaround seems to be to have two credentials for the same user. 'user@'localhost' and 'user'@'127.0.0.1'; postfix operates in a jail as well and works around the jail issue in the same way but doesn't overwrite the specified host with a reverse dns lookup. Anyone have any suggestions on how to handle this issue better? or maybe there's a way to force different behavior which I haven't yet found in the documentation? Any help is much appreciated. Best Regards.

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