October 2020 - dovecot

Strange errors after updating to 2.3.11.3
by Samuel Williams 06 Oct '20

06 Oct '20

Hello, After a recent update, I saw lots of errrors like this: Oct 05 23:55:35 mail.[redacted] dovecot[1053]: imap(samuel@[redacted])<10580><JUizN/WwWGKX0qt0>: Error: Mailbox INBOX: UID=364587: read(zlib(/srv/mail/[redacted]/samuel/mail.mdbox/storage/m.10688)) failed: read(/srv/mail/[redacted]/samuel/mail.mdbox/storage/m.10688) failed: Broken pipe (FETCH BODY[]) Oct 05 23:55:35 mail.[redacted] dovecot[1053]: imap(samuel@[redacted])<10580><JUizN/WwWGKX0qt0>: FETCH read() failed in=140 out=1440544 deleted=0 expunged=0 trashed=0 hdr_count=0 hdr_bytes=0 body_count=1 body_bytes=467441 I have been using xz compression for a long time and it has been reliable. However, the latest update seemed to corrupt some attachments. So, I downgraded back to: warning: downgrading package dovecot (2.3.11.3-2 => 2.3.10.1-2) warning: downgrading package pigeonhole (0.5.11-1 => 0.5.10-2) Now, I see a different error message: Oct 06 00:13:38 mail.[redacted] dovecot[833]: imap(samuel@[redacted])<4019><efc9ePWwgiOX0qt0>: Error: Corrupted record in index cache file /srv/mail/[redacted]/samuel/mail.mdbox/mailboxes/INBOX/dbox-Mails/dovecot.index.cache: UID 364587: Broken virtual size in mailbox INBOX: read(zlib(/srv/mail/[redacted]/samuel/mail.mdbox/storage/m.10688)): FETCH BODY[] got too little data: 467441 vs 475397 1/ Why did this happen and is there a safe way to upgrade? 2/ Is downgrading a temporary solution? 3/ Are these files lost or can I rebuild them somehow? Kind regards, Samuel

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Dsync issues since 2.3.11.3.
by Reio Remma 02 Oct '20

02 Oct '20

Hello! I've started seeing intermittent dsync failures since upgrading Dovecot to 2.3.11.3-3 (CentOS 8 using the official Dovecot repo). Sep 27 17:49:04 host dovecot[130]: dsync-local(user@host)<5GWFD2CmcF+TJwAAsNnMGQ>: Warning: Failed to do incremental sync for mailbox INBOX, retry with a full sync (Modseq 66543 no longer in transaction log (highest=66547, last_common_uid=46346, nextuid=46347)) Sep 27 17:49:04 host dovecot[130]: dsync-local(user@host)<5GWFD2CmcF+TJwAAsNnMGQ>: Error: Remote command returned error 75: ssh <options> doveadm dsync-server -u user@host It seems to happen at random times to random users. My setup has 2 servers - users are connecting to the main server and the secondary server is just for backup - noone is actually connecting to it. Any suggestions? Thanks! Reio

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Re: BUG: _presence_ of valid openssl.cnf Option = 'ServerPreference' causes Dovecot submission relay FAIL: "failed: Failed to initialize SSL: ..."
by PGNet Dev 01 Oct '20

01 Oct '20

hi, On 10/1/20 12:21 AM, JEAN-PAUL CHAPALAIN wrote: > I had the same problem when migrating from Dovecot V2.2.36 on, Centos-7 to Dovecot v2.3.8 on Centos-8 My report is specifically/solely about the addition/use of the Options = ServerPreference parameter. I don't see that in your configuration. Are you using it? In a config using Dovecot's submission proxy?

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dovecot lda deliver_log_format question
by rudolf＠padaru.de 01 Oct '20

01 Oct '20

Hey, i have an question about the deliver_log_format. My log looks sometimes like: Oct 1 09:38:01 dd44414 dovecot: lda(user)<20009><9MYzGVmHdV8pTgAA+v7NQw>: msgid=<20201001073801.628713AC05DC(a)myserver.com>: saved mail to INBOX The deliver_log_format settings are still on default. Are somebody able to explain me this part of the log message? <20009><9MYzGVmHdV8pTgAA+v7NQw>: What want dovecot to say with this? Mit freundlichen Grüßen Yours sincerely Pascal Rudolf

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debugging TLS with wireshark and a custom application ?
by Kurt Jaeger 01 Oct '20

01 Oct '20

Hi! My question is: can dovecot be used to debug/decrypt TLS sessions ? The reason I'm asking: A custom application wants to speak IMAP with TLS with a dovecot instance. It fails, and the error message is, unfortunatly, not very helpful. tcpdump shows that the session is established, but fails. The custom application says error 60000, not much more. There is a way to decode TLS sessions in some cases: https://wiki.wireshark.org/TLS using firefox and the enviroment variable SSLKEYLOGFILE. Basically, the TLS client (firefox), while negotiating keys with the other side, writes those logfiles to a logfile specified by SSLKEYLOGFILE and at the same time, wireshark is used to capture / write the pcap of the session. Then wireshark can be used to decode the contents of the TLS-encrypted session. Is something similiar possible with dovecot as the server and from the server side ? Is, by chance, the session=<...> value already such a key so that a tcpdump pcap file would be able to descrypt that session ? Sep 29 08:51:30 imap-login: Info: Login: user=<someuser>, method=PLAIN, rip=<someip>, lip=<someotherip>, mpid=63667, TLS, session=<GGF0Nm6wxy0qAQHoAAMAAwAAAAAAAAAB> -- pi(a)opsec.eu +49 171 3101372 Now what ?

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