November 2019 - dovecot

Error: proxy: Remote returned invalid banner: 220
by Marc Roos 01 Dec '19

01 Dec '19

I had a working proxy setup added sieve to it, and out of the blue I get this Error: proxy: Remote returned invalid banner: 220 No idea what to do, nothing even in the mail list archive

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dovecot: auth: Error: DNS lookup for xxx failed: Name does not resolve
by Marc Roos 01 Dec '19

01 Dec '19

I had a working container with dovecot configured as proxy. And all of a sudden I am getting these messages 'dovecot: auth: Error: DNS lookup for roosit03 failed: Name does not resolve' Pinging/nslookup these hostnames is ok

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Proxy GSSAPI + PLAIN authentication
by Sam 30 Nov '19

30 Nov '19

Hi, I try to configure a proxy accepting GSSAPI and PLAIN authentication. When authenticating with Kerberos, Dovecot uses master user and password to authenticate to backends (backends can be Cyrus or Exchange servers too) When authenticating with PLAIN passwords, Dovecot sends user's login and password to the backend. For GSSAPI, I use extrafields : k5principals=principal@REALM proxy=Y pass=masterpassword login_user=principal user=masteruser host=backend For PLAIN, I use a static driver : passdb { driver = static args = proxy=y host=cyrus password=%w } I can authenticate fine with Kerberos tickets and login/password on the backend. Trouble is that if I authenticate with PLAIN login/password, with a user known from the passdb lookup made for GSSAPI, I can authenticate with any password, it is not checked. The passdb with masteruser and nopassword=y is checked. I can't restrict the passdb with the k5principals extrafield. I tried static and ldap drivers, with the same wrong behaviour. pass_attrs = \ =proxy=Y, \ =nopassword=Y, \ =pass=masterpassword, \ =login_user=%{ldap:uid}, \ =user=masteruser, \ =host=backend, \ =k5principals=%{ldap:uid}@REALM With the ldap driver, I've got auth_bind = no The user is found in the ldap, and Dovecot logs him with the masterpassword. If I don't configure an ldap passdb, but a userdb only, the proxy try passdb that comes after for PLAIN logins. With a passwd-file driver, the k5principals works fine. The user isn't found if it authenticates with PLAIN. My question is : is it possible to restrict a ldap or static passdb for GSSAPI mechanism only ? Thanks for your help, Regards, Sam

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ESEARCH is announced but it doesn't work
by Jesus Cea 29 Nov '19

29 Nov '19

I am using Dovecot 2.3.4. I could upgrade if necessary. I see this capabilities after login in: """ a OK [CAPABILITY IMAP4rev1 SASL-IR LOGIN-REFERRALS ID ENABLE IDLE SORT SORT=DISPLAY THREAD=REFERENCES THREAD=REFS THREAD=ORDEREDSUBJECT MULTIAPPEND URL-PARTIAL CATENATE UNSELECT CHILDREN NAMESPACE UIDPLUS LIST-EXTENDED I18NLEVEL=1 CONDSTORE QRESYNC ESEARCH ESORT SEARCHRES WITHIN CONTEXT=SEARCH LIST-STATUS BINARY MOVE SNIPPET=FUZZY LITERAL+ NOTIFY SPECIAL-USE] Logged in """ ESEARCH (RFC 7377) seems to be available, but the command is not recognized: """ tag1 ESEARCH IN (mailboxes "folder1" subtree "folder2") unseen tag1 BAD Error in IMAP command ESEARCH: Unknown command (0.001 + 0.000 secs). """ What am I doing wrong? Thanks for your time and expertise. -- Jesús Cea Avión _/_/ _/_/_/ _/_/_/ jcea(a)jcea.es - http://www.jcea.es/ _/_/ _/_/ _/_/ _/_/ _/_/ Twitter: @jcea _/_/ _/_/ _/_/_/_/_/ jabber / xmpp:jcea@jabber.org _/_/ _/_/ _/_/ _/_/ _/_/ "Things are not so easy" _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ "My name is Dump, Core Dump" _/_/_/ _/_/_/ _/_/ _/_/ "El amor es poner tu felicidad en la felicidad de otro" - Leibniz

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sendmail -> lmtp 501 5.6.0 Data format error
by Marc Roos 28 Nov '19

28 Nov '19

When changing in a working setup sendmail.mc From this MAILER(smtp)dnl MAILER(procmail)dnl To this FEATURE(`local_lmtp',`[IPC]',`FILE /var/run/dovecot/lmtp')dnl MAILER(local)dnl I am getting these errors '501 5.6.0 Data format error' and ' Unrecognized host name'. What should I change in my lmtp config? Could this be related that messages are being relayed from other servers? lmtp_address_translate = lmtp_hdr_delivery_address = final lmtp_proxy = no lmtp_rcpt_check_quota = no lmtp_save_to_detail_mailbox = no lmtp_user_concurrency_limit = 0

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Using dovecot Replication in a medium to large enterprise.
by Brent Clark 28 Nov '19

28 Nov '19

Good day Guys Just wanted to pick the communities brain and experience(s) for a second. At $CORP where I work. My team has inherited a single server mail solution. We need to look to building a standby / replicated solution. One of the things we were looking at is https://wiki.dovecot.org/Replication We have in excess of +/- 500 mail boxes and using just under 1TB of disk space. That is a lot of small files. Reading about this plugin / module, things that stick out and is concerning is the comments: "The replication in general is a bit resource intensive, so it's not recommended to be used in multi-million user installations." "WARNING: Shared folder replication doesn't work correctly right now –" I would like to ask the community (and anyone else in a similar enterprise) how and if this solution works and scales. In short, I am asking, is anyone else using Dovecot Replication in a medium to large enterprise? Can you please share your experiences, pitfalls and if you have any tips managing mail replication. Kindest regards and thanks in advance. Brent Clark

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IMAP Migration Tools
by Julian Kippels 28 Nov '19

28 Nov '19

Hi, I am looking for tools to migrate Mails from one IMAP-Server to another. Until now I have always used imapsync, but it seems very slow. Even over a 2x10GB/s connection I only get speeds of about 600KiB/s, because the programm always pauses betweeen every single mail. Does anyone here have a suggestion for an alternative? Thanks in advance Julian

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Sendmail + lmtp
by Marc Roos 28 Nov '19

28 Nov '19

Is there any guide like this https://wiki.dovecot.org/HowTo/PostfixDovecotLMTP for configuring sendmail?

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Dovecot auth
by j.emerlik 27 Nov '19

27 Nov '19

Hi, is possible to configure post-login script for Service auth ? I would like to run post script after successful login to postfix (smtp). Regards, Jack

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Dovecot FINs after sending "NO Not showing other users' quota"
by Gene Smith 27 Nov '19

27 Nov '19

When I do imap getquota on a shared folder I see the NO response. That's OK but then often dovecot disconnects (sends FIN) to the client right after this. The client acks the disconnect and creates a new connection and continues on. Should dovecot disconnect after this type of imap "NO" response? -gene

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