- dovecot - dovecot.org

SIS and tracing the origin of an attachment
by doug 16 Mar '22

16 Mar '22

Hi All, I'm trying to trace an attachment within an SIS subdirectory to the email message(s) that link to it. I say messages because I'm also using dovecot dedup. My understanding is the linked file name is the hash value of the attachments contents concatenated with the GUID of the email message. I have had marginal success with a message I created myself. Example: I generated an email with two attachments. Here are the links in my attachment directory. ./26/c5/26c5c540d41779d83d2f5388041d05c67d720d9a-73eca8051acd276272310000f2bc99a3 ./65/cd/65cd73112a489ef07f17ed5740aa60358e2dd3fb-74eca8051acd276272310000f2bc99a3 In my sent folder the actual GUID of the message is 75eca8051acd276272310000f2bc99a3. So the GUID of the attachment is based on the GUID of the message, but not exact. The second hex byte seems to be decremented as an offset of the attachment index from the GUID of the message. At least in my one example. # doveadm dump /mailstore/doug/mail/mailboxes/Sent/dbox-Mails/dovecot.index | grep guid | tail -1 - guid: 75eca8051acd276272310000f2bc99a3 With that actual GUID I can find the message with a search: # doveadm search -u doug mailbox Sent guid 75eca8051acd276272310000f2bc99a3 doug e5711f1cf2c9294f71090000059b96e4 53526 Now let's try to track down another email when only the HASH-GUID value is known. Here is one randomly picked. ./00/a2/00a2d5de3e41053d59bd10084826bbe094aa1c59-57857b09d1a327627e260000f2bc99a3 # doveadm search -A mailbox '*' guid 57857b09d1a327627e260000f2bc99a3 # doveadm search -A mailbox '*' guid 58857b09d1a327627e260000f2bc99a3 # doveadm search -A mailbox '*' guid 59857b09d1a327627e260000f2bc99a3 I repeated this incrementing and decrementing from 5085... through 5f85... and never located the message. This seems like it should be trivial but I've been struggling with it for days. The GUID isn't random, there must be a way to track the attachment back. What am I missing? And for those wondering why, our virus scanner flagged a number of attachments, some with several links, and I want ask the users to delete the offending messages so I can purge them from the server. If I can find the emails I can give them the mail folder, date/time, and subject of the message. -- Doug

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AW: [EXT] AW: AW: AW: invalid lz4 chunk size??
by Joachim Lindenberg 16 Mar '22

16 Mar '22

What might go wrong? Or should I copy the directory myself from remote? What can go wrong with that? Thanks, Joachim -----Ursprüngliche Nachricht----- Von: Aki Tuomi <aki.tuomi(a)open-xchange.com> Gesendet: Wednesday, 16 March 2022 11:31 An: Joachim Lindenberg <dovecot(a)lindenberg.one> Betreff: Re: [EXT] AW: AW: AW: invalid lz4 chunk size?? It might, I can't promise it =) Aki > On 16/03/2022 12:29 Joachim Lindenberg <dovecot(a)lindenberg.one> wrote: > > > With remote I am referring to the second instance of mailcow including dovecot I am running, which has dovecot replication active. I am observing the issue on just one box. Thus I am hoping that when I remove the user mail directory on one host, replication will restore it from remote. > Thanks, Joachim > > -----Ursprüngliche Nachricht----- > Von: Aki Tuomi <aki.tuomi(a)open-xchange.com> > Gesendet: Wednesday, 16 March 2022 11:17 > An: Joachim Lindenberg <dovecot(a)lindenberg.one>; dovecot(a)dovecot.org > Betreff: Re: AW: AW: invalid lz4 chunk size?? > > Not sure what "remote" you are talking about. You can remove the file, and dovecot will notice it's absence and update it's indexes if this is maildir++ format. > > If this is sdbox, you need to run `doveadm force-resync -u user FolderName`. > > Aki > > > On 16/03/2022 12:08 Joachim Lindenberg <dovecot(a)lindenberg.one> wrote: > > > > > > Hi Aki, > > sure I can delete (or rename) the file(s) in the mail directory. > > Will sync then restore it from remote or should I do this manually? Should I stop dovecot during the process?` I am not very familiar with dovecot yet, as most of the complexity is hidden by mailcow. > > Thanks, Joachim > > > > -----Ursprüngliche Nachricht----- > > Von: Aki Tuomi <aki.tuomi(a)open-xchange.com> > > Gesendet: Wednesday, 16 March 2022 08:38 > > An: Joachim Lindenberg <dovecot(a)lindenberg.one>; dovecot(a)dovecot.org > > Betreff: Re: AW: invalid lz4 chunk size?? > > > > Hi, > > > > looks a lot like your mail file is corrupted. Not much you can do about it other than maybe delete the file? You can try recover it with `doveadm fetch -u someone text uid 1553 mailbox Sent` and then using `doveadm save -u someone -m Sent` to store it back. > > > > Aki > > > > > On 16/03/2022 09:35 Joachim Lindenberg <dovecot(a)lindenberg.one> wrote: > > > > > > > > > Nobody that can help? > > > Thanks, > > > Joachim > > > > > > ---------- > > > > > > I am still experiencing the issue. Any suggestion? > > > As I do have replication between two nodes and only one is showing the issue - can I rename the mailbox easily on one side and rely on replication to get the copy replaced? If that makes sense, which commands do you recommend? > > > Thanks, > > > Joachim > > > > > > -----Ursprüngliche Nachricht----- > > > Von: Joachim Lindenberg <dovecot(a)lindenberg.one> > > > Gesendet: Thursday, 3 March 2022 12:06 > > > An: 'Aki Tuomi' <aki.tuomi(a)open-xchange.com>; dovecot(a)dovecot.org > > > Betreff: AW: invalid lz4 chunk size?? > > > > > > dovecot --version reports 2.3.17.1 (476cd46418) Joachim > > > > > > -----Ursprüngliche Nachricht----- > > > Von: Aki Tuomi <aki.tuomi(a)open-xchange.com> > > > Gesendet: Thursday, 3 March 2022 11:56 > > > An: Joachim Lindenberg <dovecot(a)lindenberg.one>; > > > dovecot(a)dovecot.org > > > Betreff: Re: invalid lz4 chunk size?? > > > > > > > > > > On 03/03/2022 12:24 Joachim Lindenberg <dovecot(a)lindenberg.one> wrote: > > > > > > > > > > > > Hello, > > > > when accessing one mailbox via ActiveSync / SoGo / Dovecot I get the following error repeatedly in dovecot log: > > > > imap(somemailbox(a)example.org)<1579><***>: Error: Mailbox Sent: > > > > UID=1553: read(compress()) failed: read() failed: lz4.read(): invalid lz4 chunk size: 1601505441 at 16842752 (read reason=) I can still access the mailbox via IMAP though. > > > > What can I do to resolve the issue? > > > > Thanks, > > > > Joachim > > > > > > Which version of Dovecot? > > > > > > Aki

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invalid lz4 chunk size??
by Joachim Lindenberg 16 Mar '22

16 Mar '22

Hello, when accessing one mailbox via ActiveSync / SoGo / Dovecot I get the following error repeatedly in dovecot log: imap(somemailbox(a)example.org)<1579><***>: Error: Mailbox Sent: UID=1553: read(compress()) failed: read() failed: lz4.read(): invalid lz4 chunk size: 1601505441 at 16842752 (read reason=) I can still access the mailbox via IMAP though. What can I do to resolve the issue? Thanks, Joachim

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sieve-filter not respecting :create flag of fileinto
by David Arroyo 16 Mar '22

16 Mar '22

Hello, I recently significantly modified my sieve rules for filing mailing list posts in my Fastmail inbox. The rules contain a few rules that file mail like so: fileinto :create ml.${5}${4}{$3}{$2}{$1}; # reversed list-id The rules work as expected on delivery to fastmail. Because these rules only run on delivery, and the new folder layout is different from my existing one, I want to apply the rules to my existing mail. I thought dovecot's `sieve-filter` command, together with the `imapc` storage backend, would be a good way to do that, so I moved some existing mail into a folder, `sieve-test`, and ran the following: sieve-filter -x '+editheader +mailbox' -W -e rules.sieve sieve-test However, what I see is that sieve-filter fails when the new directory does not exist. Here is some example (redacted) output: Info: imapc(imap.fastmail.com:993): Connected to x.x.x.x:993 (local x.x.x.x) error: msgid=<xxx>: fileinto action: failed to store into mailbox 'ml.gnu.guix-devel': Mailbox does not exist. sieve-filter(me): Info: sieve: msgid=<xxx>: left message in mailbox 'sieve-test' error: sieve script execution failed for this message; message left in source mailbox. sieve-filter(me): Info: sieve: msgid=<yyy>: fileinto action: stored mail into mailbox 'ml.9fans.9fans' My config looks like this: protocols = none mail_location = imapc: namespace { inbox = yes separator = . } imapc_host = imap.fastmail.com imapc_port = 993 imapc_ssl = imaps imapc_user = $username If this is a bug in sieve-filter I'd be happy to try and fix it, but I'm reaching out here first to see if this is expected behavior or a misconfiguration on my part. Thanks for any help, David

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mdbox_rotate_size recommendation / performance
by Lucas Rolff 15 Mar '22

15 Mar '22

Hi guys, When using mdbox under Dovecot, the mdbox_rotate_size setting defaults to 10 megabyte - from a performance point of view if using spinning drives does this matter whether one goes for e.g. 2MB versus 10MB, especially in the combination with compression. Does anyone have any performance data regarding it’s size, and what’s a decent trade-off between limiting IOPS required by the drive versus the sequential read/write speeds. Any pointers would be awesome! Thanks in advance

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AntiVirus in Maildir
by Masakazu Hirose 15 Mar '22

15 Mar '22

Hi all, I run a mail server on Maildir. Does Dovecot work correctly if I delete the mail files stored in Maildir? Do I need to run the doveadm command? I want to run a virus scan on Maildir. When a virus is detected, the mail file is deleted without notifying Dovecot. I assumed this was incorrect behavior for Dovecot. Please help me when someone has time. Thanks, Masa

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allow_nets equivalent for all users?
by Bryan K. Walton 14 Mar '22

14 Mar '22

Hi, It is my understanding that allow_nets is a field that gets used in a password database, and therefore is a per-user setting. Is there an equivalent method for defining allowed network(s) for ALL users? In other words, a single setting that applies to every user? Thanks, Bryan

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Possible bug interaction between Dovecot and Thunderbird 98/99 email client
by Arthur Koziol 11 Mar '22

11 Mar '22

Hi Dovecot devs, My name is Arthur. I'm a volunteer with Mozilla and am working with a user who's having some odd issues with his Thunderbird email client. I'm reaching out to you folks because he's using an at-home IMAP setup with Dovecot. It's not 100% clear if his setup is polling his GMail accounts and then pulling everything to his Dovecot setup but if there's any interesting in jumping into the bug we're trying to help this user with, feel free to browse the bug at https://bugzilla.mozilla.org/show_bug.cgi?id=1726319 I asked the user if he's reached out to the Dovecot devs yet but he's not replied. We're not sure if this is a Dovecot / setup issue, a Thunderbird issue or something in between but we could use some other eyes and ideas of what to check for this user if you guys have a couple seconds to take a look. Thanks for reading. best, Arthur

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Dovecot High Availability ?
by White, Daniel E. (GSFC-770.0)[NICS] 11 Mar '22

11 Mar '22

Are there any current, free high availability strategies for Dovecot ?

2 1

Can't create viable password hashes
by David Griffith 11 Mar '22

11 Mar '22

I recently discovered that I can no longer create viable password hashes for use in /etc/dovecot/dovecot.passwd. So far, I've been using the following command done by root: doveadm_cmd pw -s SHA512-CRYPT -u joe -p mypassword This creates something that looks legit, but dovecot won't accept it. I've been using my own solution for allowing users to change their dovecot passwords (https://gitlab.com/DavidGriffith/dovepasswd) and this is how it generates the hashes. Is there a better way of going about this? -- David Griffith dave(a)661.org A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

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