November 2023 - dovecot

RE: How to temporarily make all mailboxes read-only for backup purposes?
by Matthias Nagel 25 Nov '23

25 Nov '23

> Why would you want to do that? Afaik sdbox stores email per file. There is also an index file which stores meta attributes per mail/file and I want them to be consistent. > The mta just delivers the email later and your backup is already old. That's not really am argument. Just imagine the mail would have been sent some moment later after the backup has been started. In that case the mail wouldn't be in the backup either. A backup on a regular schedule for catastrophe recovery always has the "issue" that it will be old by half the time of the schedule on average in case one really needs it. Regarding snapshots on ZFS an similar file system: Not an option as I am using a shared hoster and the file system does not allow snapshots. Am 22. November 2023 21:46:19 schrieb Marc <Marc(a)f1-outsourcing.eu>: > Why would you want to do that? Afaik sdbox stores email per file. The mta > just delivers the email later and your backup is already old. Are you > making a snapshot and backup that, that is a very short time window. > >> >> I am using Dovecot sdbox format for mailboxes. Is there an option to >> temporarily make Dovecot read-only while the mailboxes are being backed-up >> such that a consistent state is backed-up? >> >> I am looking for some command which I can use as pre- and post-hook for >> Borgbackup. I am looking for a way such that Dovecot defers any mail coming >> in via LMTP from Postfix, denies modifying mails/mailboxes via IMAP while >> Dovecot still allows to browse mails read-only.

2 1

How to temporarily make all mailboxes read-only for backup purposes?
by Matthias Nagel 24 Nov '23

24 Nov '23

Dear all, I am using Dovecot sdbox format for mailboxes. Is there an option to temporarily make Dovecot read-only while the mailboxes are being backed-up such that a consistent state is backed-up? I am looking for some command which I can use as pre- and post-hook for Borgbackup. I am looking for a way such that Dovecot defers any mail coming in via LMTP from Postfix, denies modifying mails/mailboxes via IMAP while Dovecot still allows to browse mails read-only. Is that possible? Bests, Matthias

2 1

Ouath2 compatible mail clients
by Francis Augusto Medeiros-Logeay 23 Nov '23

23 Nov '23

Hi, Are there any oauth2 compatible mail clients out there? For Mac/iOS? I see that Mail for Mac supports it, but just for Exchange. __ Francis Augusto Medeiros-Logeay Oslo, Norway Sent from a mobile device / Enviado a partir de dispositivo móvel Hi, Are there any oauth2 compatible mail clients out there? For Mac/iOS? I see that Mail for Mac supports it, but just for Exchange. __ Francis Augusto Medeiros-Logeay Oslo, Norway Sent from a mobile device / Enviado a partir de dispositivo móvel

1 0

[CFP] "Modern Email" Developer Room at FOSDEM '24
by Joris Baum 23 Nov '23

23 Nov '23

Hi, There will be a developer room that I think will be of particular interest for subscribers of this mailing list for "Modern Email" during FOSDEM '24. It will center around the current state of email, free/open source software projects related to email and current developments. FOSDEM is and event for free software and open source developers. The event encompasses two main streams: talks curated by organizers covering diverse topics and the developer rooms. Spread across multiple buildings at the venue, the developer rooms are focusing on specific concepts, technologies, and ideas. This is where the fun is. And most of the fun will obviously happen in the "Modern Email" room. The submission deadline for proposals is 1st December 2023. You can find more info on GitHub: https://github.com/modern-email/FOSDEM-24 . Regards, Joris Baum -- Joris Baum Tel: +49 721 170293 16 Fax: +49 721 170293 179 http://www.audriga.com | http://www.twitter.com/audriga -------------------------------------------------------------------------- audriga GmbH | Alter Schlachthof 57 | 76137 Karlsruhe Sitz der Gesellschaft: Karlsruhe - Amtsgericht Mannheim - HRB 713034 Geschäftsführer: Dr. Frank Dengler, Dr. Hans-Jörg Happel --------------------------------------------------------------------------

2 2

Anyone Watching Actvity from this network? Attempting Dovecot Buffer Overflows?
by Michael Peddemors 21 Nov '23

21 Nov '23

There is a network claiming to be a security company, however the activity appears to be a little more malicious, and appears to be attempting buffer overflows against POP-SSL services.. (and other attacks). https://www.abuseipdb.com/check/104.156.155.21 Just thought it would be worth mentioning, you might want to keep an eye out for traffic from this company... Might want to make up your own mind, or maybe someone has more information, but enough of a red flag, that thought it warranted posting on the list. Not sure yet if it is Dovecot, or the SSL libraries they are attempting to break, but using a variety of SSL/TLS methods and connections... Anyone with more information? NetRange: 104.156.155.0 - 104.156.155.255 CIDR: 104.156.155.0/24 NetName: ACDRESEARCH NetHandle: NET-104-156-155-0-1 Parent: NET104 (NET-104-0-0-0-0) NetType: Direct Allocation OriginAS: Organization: Academy of Internet Research Limited Liability Company (AIRLL) RegDate: 2022-01-07 Updated: 2022-01-07 Ref: https://rdap.arin.net/registry/ip/104.156.155.0 OrgName: Academy of Internet Research Limited Liability Company OrgId: AIRLL Address: #A1- 5436 Address: 1110 Nuuanu Ave City: Honolulu StateProv: HI PostalCode: 96817 Country: US RegDate: 2021-10-15 Updated: 2022-11-06 Ref: https://rdap.arin.net/registry/entity/AIRLL -- "Catch the Magic of Linux..." ------------------------------------------------------------------------ Michael Peddemors, President/CEO LinuxMagic Inc. Visit us at http://www.linuxmagic.com @linuxmagic A Wizard IT Company - For More Info http://www.wizard.ca "LinuxMagic" a Registered TradeMark of Wizard Tower TechnoServices Ltd. ------------------------------------------------------------------------ 604-682-0300 Beautiful British Columbia, Canada This email and any electronic data contained are confidential and intended solely for the use of the individual or entity to which they are addressed. Please note that any views or opinions presented in this email are solely those of the author and are not intended to represent those of the company.

11 15

dovecot and oauth2 (with keycloak) not working
by Francis Augusto Medeiros-Logeay 20 Nov '23

20 Nov '23

Hi, I successfully configured Roundcube to use keycloak for oauth2. However, I am having trouble to make it work with dovecot. My configuration is this: cat dovecot-oauth2.conf.ext tokeninfo_url = https://auth.mydomain.com/realms/myrealm/protocol/openid-connect/userinfo introspection_url = https://auth.mydomain.com/realms/myrealm/protocol/openid-connect/token/intr… introspection_mode = post username_attribute = postfixMailAddress debug = yes scope = openid Roundcube_email This is what I am getting from the logs: Nov 20 08:20:30 auth: Error: ldap(francis(a)mydomain.com,10.10.40.30,<yskzUpAKb9EKCige>): ldap_bind() failed: Constraint violation Nov 20 08:20:30 auth: Debug: http-client: host auth.mydomain.com: Host created Nov 20 08:20:30 auth: Debug: http-client: host auth.mydomain.com: Host session created Nov 20 08:20:30 auth: Debug: http-client: host auth.mydomain.com: IPs have expired; need to refresh DNS lookup Nov 20 08:20:30 auth: Debug: http-client: host auth.mydomain.com: Performing asynchronous DNS lookup Nov 20 08:20:30 auth: Debug: http-client[1]: request [Req1: GET https://auth.mydomain.com/realms/med-lo/protocol/openid-connect/userinfoeyJ…] Submitted (requests left=1) Nov 20 08:20:30 auth: Debug: http-client: host auth.mydomain.com: DNS lookup successful; got 1 IPs Nov 20 08:20:30 auth: Debug: http-client: peer 10.10.100.10:443 (shared): Peer created Nov 20 08:20:30 auth: Debug: http-client: peer 10.10.100.10:443: Peer pool created Nov 20 08:20:30 auth: Debug: http-client[1]: peer 10.10.100.10:443: Peer created Nov 20 08:20:30 auth: Debug: http-client[1]: queue https://auth.mydomain.com:443: Setting up connection to 10.10.100.10:443 (SSL=auth.mydomain.com) (1 requests pending) Nov 20 08:20:30 auth: Debug: http-client[1]: peer 10.10.100.10:443: Linked queue https://auth.mydomain.com:443 (1 queues linked) Nov 20 08:20:30 auth: Debug: http-client[1]: queue https://auth.mydomain.com:443: Started new connection to 10.10.100.10:443 (SSL=auth.mydomain.com) Nov 20 08:20:30 auth: Debug: http-client[1]: peer 10.10.100.10:443: Creating 1 new connections to handle requests (already 0 usable, connecting to 0, closing 0) Nov 20 08:20:30 auth: Debug: http-client[1]: peer 10.10.100.10:443: Making new connection 1 of 1 (0 connections exist, 0 pending) Nov 20 08:20:30 auth: Debug: http-client: conn 10.10.100.10:443 [1]: Connecting Nov 20 08:20:30 auth: Debug: http-client: conn 10.10.100.10:443 [1]: Waiting for connect (fd=23) to finish for max 0 msecs Nov 20 08:20:30 auth: Debug: http-client: conn 10.10.100.10:443 [1]: HTTPS connection created (1 parallel connections exist) Nov 20 08:20:30 auth: Debug: http-client: conn 10.10.100.10:443 [1]: Client connection failed (fd=23) Nov 20 08:20:30 auth: Debug: http-client[1]: peer 10.10.100.10:443: Connection failed (1 connections exist, 0 pending) Nov 20 08:20:30 auth: Debug: http-client: peer 10.10.100.10:443: Failed to make connection (1 connections exist, 0 pending) Nov 20 08:20:30 auth: Debug: http-client[1]: peer 10.10.100.10:443: Failed to establish any connection within our peer pool: connect(10.10.100.10:443) failed: Connection refused (1 connections exist, 0 pending) Nov 20 08:20:30 auth: Debug: http-client[1]: queue https://auth.mydomain.com:443: Failed to set up connection to 10.10.100.10:443 (SSL=auth.mydomain.com) connect(10.10.100.10:443) failed: Connection refused (1 peers pending, 1 requests pending) Nov 20 08:20:30 auth: Debug: http-client[1]: peer 10.10.100.10:443: Unlinked queue https://auth.mydomain.com:443 (0 queues linked) Nov 20 08:20:30 auth: Debug: http-client[1]: queue https://auth.mydomain.com:443: Failed to set up any connection; failing all queued requests Nov 20 08:20:30 auth: Debug: http-client[1]: request [Req1: GET https://auth.mydomain.com/realms/med-lo/protocol/openid-connect/userinfoeyJ…] Error: 9003 connect(10.10.100.10:443) failed: Connection refused Nov 20 08:20:30 auth: Debug: http-client[1]: queue https://auth.mydomain.com:443: Dropping request [Req1: GET https://auth.mydomain.com/realms/med-lo/protocol/openid-connect/userinfoeyJ…] Nov 20 08:20:30 auth: Error: oauth2(francis(a)mydomain.com,10.10.40.30,<yskzUpAKb9EKCige>): oauth2 failed: connect(10.10.100.10:443) failed: Connection refused Nov 20 08:20:30 auth: Debug: http-client[1]: request [Req1: GET https://auth.mydomain.com/realms/med-lo/protocol/openid-connect/userinfoeyJ…] Destroy (requests left=1) Nov 20 08:20:30 auth: Debug: http-client[1]: request [Req1: GET https://auth.mydomain.com/realms/med-lo/protocol/openid-connect/userinfoeyJ…] Free (requests left=0) Nov 20 08:20:30 auth: Debug: http-client: conn 10.10.100.10:443 [1]: Connection close Nov 20 08:20:30 auth: Debug: http-client: conn 10.10.100.10:443 [1]: Connection disconnect Nov 20 08:20:30 auth: Debug: http-client: conn 10.10.100.10:443 [1]: Disconnected: connect() failed: Connection refused (fd=23) Nov 20 08:20:30 auth: Debug: http-client: conn 10.10.100.10:443 [1]: Detached peer Nov 20 08:20:30 auth: Debug: http-client: conn 10.10.100.10:443 [1]: Connection destroy Nov 20 08:20:32 imap-login: Info: Disconnected (auth service reported temporary failure): user=<francis(a)mydomain.com>, method=XOAUTH2, rip=10.10.40.30, lip=172.18.0.10, TLS, session=<yskzUpAKb9EKCige> My dovecot version is 2.3.7.2 (3c910f64b). I find it odd that it is sending the token as a parameter, when I chose “post” as the introspection mode. But I don’t know if that is the problem. best, Francis

3 6

Avoiding POODLE vulnerability
by Steve Litt 20 Nov '23

20 Nov '23

Hi all, Ten years after the fact I learned about POODLE (Padding Oracle On Downgraded Legacy Encryption) vulnerabilities, which enable a poorly configured server to force my client to downgrade to vulnerable encryption. My current conf.d/10-ssl.conf contains the following line: ssl_cipher_list = ALL:!LOW:!SSLv3:!EXP:!aNULL I've read that I should change the preceding line to the following: ssl_protocols = !SSLv3 !SSLv2 Is this correct? For some reason I have the same ssl_cipher_list in dovecot.conf. Should I make the change there too? Is there anything else I need to change? The following is my current dovecot.conf: ================================================= # 2.3.13 (89f716dc2): /etc/dovecot/dovecot.conf # OS: Linux 5.10.12_1 x86_64 # Hostname: mydesk.domain.cxm mail_location = maildir:~/mail/Maildir:INBOX=~/mail/Maildir/.INBOX namespace inbox { inbox = yes location = prefix = } passdb { driver = pam args = %s } userdb { driver = passwd } protocols = imap service imap-login { inet_listener imap { #port = 143 port = 0 } inet_listener imaps { port = 993 #port = 0 ssl = yes #ssl = no } } ssl = required #ssl = yes ssl_cert = </etc/ssl/dovecot_certs/certs/dovecot.pem ssl_cipher_list = ALL:!LOW:!SSLv3:!EXP:!aNULL ssl_key = </etc/ssl/dovecot_certs/private/dovecot.pem ================================================= By the way, does the preceding dovecot.conf even use the files in directories off conf.d ? Thanks, SteveT Steve Litt Autumn 2023 featured book: Rapid Learning for the 21st Century http://www.troubleshooters.com/rl21

3 8

passdb doesn't support credential lookups
by Michael Grant 20 Nov '23

20 Nov '23

I'm having trouble authenticating certain users. I see this in the logs: Nov 19 16:26:40 auth: Debug: pam(jane,192.168.2.83,<...>): Performing passdb lookup Nov 19 16:26:40 auth: Debug: pam(jane,192.168.2.83,<...>): passdb doesn't support credential lookups Nov 19 16:26:40 auth: Debug: pam(jane,192.168.2.83,<...>): Finished passdb lookup at the command line, if I run this: % doveadm auth login jane Password: passdb: jane auth succeeded Oddly, I have a handfull of users that are failing and others that are not and I don't see the difference.

1 0

Re: DMARC Failures for Mailing List
by dovecot＠x9p.org 18 Nov '23

18 Nov '23

On 11/17/23 10:38, Nick Lockheart wrote: > The DKIM check is also failing. I think the list software may be re-writing the > message bodies. I believe one of the reasons for the DKIM failure is this addition/configuration by mailman in the footer of every message (the unsubscribe stuff): >>>>>>>> _______________________________________________ dovecot mailing list --dovecot(a)dovecot.org To unsubscribe send an email todovecot-leave(a)dovecot.org >>>>>>>> --x9p On 11/17/23 10:38, Nick Lockheart wrote: The DKIM check is also failing. I think the list software may be re- writing the message bodies. I believe one of the reasons for the DKIM failure is this addition/ configuration by mailman in the footer of every message (the unsubscribe stuff): >>>>>>>> _______________________________________________ dovecot mailing list -- dovecot(a)dovecot.org To unsubscribe send an email to dovecot-leave(a)dovecot.org >>>>>>>> --x9p

1 0

DMARC Failures for Mailing List
by Nick Lockheart 18 Nov '23

18 Nov '23

Now that we've got our new mail server going and the DMARC reports are coming in, I'm finding a lot of DMARC failures for messages that I'm sending to this list. It seems that when I send a message to this list, the list software forwards it to other people on my behalf, but uses my email address in the header_from. This results in an SPF failure, because SPF only allows our MX to send mail for our domain. The DKIM check is also failing. I think the list software may be re- writing the message bodies. Another user that I replied to on this list a day ago said my list mail went to spam on his gmail. 1. Will our domain reputation be harmed by having a lot of copies of the same messages going to a bunch of different people on different ISPs and all of them failing DMARC? It seems that some places are using databases that look for duplicate content sent to multiple recipients to identify bulk mail and spam. 2. Is there any way to mitigate DMARC issues for mailing lists? It seems like the mailing list software should be sending out the emails as itself, not as the user that submitted the message. Now that we've got our new mail server going and the DMARC reports are coming in, I'm finding a lot of DMARC failures for messages that I'm sending to this list. It seems that when I send a message to this list, the list software forwards it to other people on my behalf, but uses my email address in the header_from. This results in an SPF failure, because SPF only allows our MX to send mail for our domain. The DKIM check is also failing. I think the list software may be re-writing the message bodies. Another user that I replied to on this list a day ago said my list mail went to spam on his gmail. 1. Will our domain reputation be harmed by having a lot of copies of the same messages going to a bunch of different people on different ISPs and all of them failing DMARC? It seems that some places are using databases that look for duplicate content sent to multiple recipients to identify bulk mail and spam. 2. Is there any way to mitigate DMARC issues for mailing lists? It seems like the mailing list software should be sending out the emails as itself, not as the user that submitted the message.

4 3