- Mailman-users - lists.mailman3.org

Mass subscription: HTTP Error 400: 'pathlib._local.PosixPath' object does not support the context manager protocol
by Flo June 23, 2026

June 23, 2026

Hi, Debian trixie, virtualenv installation: When I entered addresses at the mass subscription field I got: HTTP Error 400: 'pathlib._local.PosixPath' object does not support the context manager protocol The addresses were subscribed though. How can I have subscription working correctly? I haven't found anything reasonable on the Internet. Thank you for your help! Flo

1 0

Server error,An error occurred while processing your request. - SITE_ID
by Flo June 23, 2026

June 23, 2026

Hi, I did the virtualenv installation on Debian trixie. I got mailmanweb running, created a superuser, could login into https://my.site.net/admin (after resolving CSRF errors). I created a new site (my.site.net) in Django, deleted example.com and changed SITE_ID to 0 in /etc/mailman3/settings.py . After restarting mailman3 and mailmanweb services I get Server error,An error occurred while processing your request. when I call https://my.site.net/admin again. Even if I change SITE_ID back to 1 there is no change. What have I done wrong? I haven't found any solution on the internet. And, even more important, how get I get it working again? Thank you for your help. Flo.

3 5

Shutdown problem
by Lars Bjørndal June 22, 2026

June 22, 2026

Sometimes when I reboot the machine, I experience that mailman doesn't start because the files /opt/mailman3/mm/var/locks/master.lck* isn't deleted during shutdown. Maybe one way to solve this could be to use ExecStartPre directive in the systemd service to remove the lock files. What's the best practice to solve this problem? BTW I've noticed that doing `systemctl stop mailman3` takes a very long time, 45 secs. or something like that. - Mailman 3.3.10 - Python 3.12.13 ``` /etc/systemd/system/mailman3.service [Unit] Description=GNU Mailing List Manager After=syslog.target network.target postgresql.service [Service] Type=forking PIDFile=/opt/mailman3/mm/var/master.pid User=mailman3 Group=mailman3 Environment="MAILMAN_CONFIG_FILE=/etc/mailman3/mailman.cfg" ExecStart=/opt/mailman3/venv/bin/mailman start ExecReload=/opt/mailman3/venv/bin/mailman restart ExecStop=/opt/mailman3/venv/bin/mailman stop # Tested, but have no effect on deletion of the lock file. #Restart=on-failure #RestartSec=15 [Install] WantedBy=multi-user.target ``` Lars

5 10

postfix_lmtp doesn't exist
by Flo June 17, 2026

June 17, 2026

Dear all, I am running Debian Trixie with Postfix. Now I want to install Mailman via virtualenv. All looks fine so far but when I insert transport_maps = hash:/home/mailman_var/data/postfix_lmtp local_recipient_maps = hash:/home/mailman_var/data/postfix_lmtp relay_domains = hash:/home/mailman_var/data/postfix_domains to main.cf I get an error when sending emails. Understandable, because there is no postfix_lmtp available. When will it be created? I haven't observed any error at the installation up to that point. Thanks for your help, Flo PS: I changed var_dir to /home/mailman_var because I thought data should be better at the home partition, especially as I was afraid they might take a lot of space and there is not a lot available at the root partition. I don't know if this is a good idea.

2 3

Possibly more a Postfix question than a mailman one one but...
by Paul Tomblin June 15, 2026

June 15, 2026

I want to limit the number of simultanous connections for one domain that I send email to. According ot what i've managed to find on-line, I need to put in a transport map in Postfix for that. But Mailman appears to already be using the transport map for routing incoming mail: > > transport_maps = > hash:/opt/mailman/mm/var/data/postfix_lmtp > local_recipient_maps = > proxy:unix:passwd.byname, $alias_maps, hash:/opt/mailman/mm/var/data/postfix_lmtp > relay_domains = > hash:/opt/mailman/mm/var/data/postfix_domains Can i append or pre-pend another transport file in the transport_maps listing and put in the entry for this domain that's been bouncing people off my list because of too many simultaneous connections? -- Paul Tomblin

3 7

Why aren't I getting bounce texts any more?
by Paul Tomblin June 9, 2026

June 9, 2026

I swear I used to get the exactly text of the bounce message when email to a list member bounced, but I'm not seeing it any more. Is there a setting I've overlooked? I've turned on "*Notify owner on bounce increment"* which was off for some reason. I just had 24 users bounced off a mailing list this morning for excessive bounces, and I can only think their ISP suddenly took exception to my setup somehow. It would have been nice to have to a warning when the first bounce happened. -- Paul Tomblin

3 5

Generic Cannot connect to SMTP server error, no outgoing smtp connections
by Stefan Bauer June 4, 2026

June 4, 2026

Dear Users, I'm debugging since several days a mailman3 installation and can not get mailman to deliver mails to list members. Mailman logs Cannot connect to SMTP server, however the server is listening, but i see no connection attempts. In queue/out, i see changing files all the time: drwxrwx--- 2 mailman nogroup 4.0K Jun 4 13:04 . drwxr-xr-x 15 mailman nogroup 4.0K Jun 4 08:22 .. -rw-rw---- 1 mailman nogroup 6.1K Jun 4 12:22 1780575734.9281623+0ad5f564c9fc5f27750a09b948f3480d9047cbaa.pck.tmp -rw-rw---- 1 mailman nogroup 6.1K Jun 4 13:04 1780578250.2070453+752ca17af5c64af7aab5f0fc61ac2ea28b091825.bak 038b90c74d8d:/opt/mailman/var/queue/out# ls -alh total 24K drwxrwx--- 2 mailman nogroup 4.0K Jun 4 13:04 . drwxr-xr-x 15 mailman nogroup 4.0K Jun 4 08:22 .. -rw-rw---- 1 mailman nogroup 6.1K Jun 4 12:22 1780575734.9281623+0ad5f564c9fc5f27750a09b948f3480d9047cbaa.pck.tmp -rw-rw---- 1 mailman nogroup 6.1K Jun 4 13:04 1780578250.7552953+6350a013583657c317c0a64b9cf2039dca645974.bak 038b90c74d8d:/opt/mailman/var/queue/out# SMTP/DEBUG-Log is flooded with over and over same attempts: ==> /opt/mailman/core/var/logs/smtp.log <== Jun 04 13:04:46 2026 (26) Using agent: <mailman.mta.deliver.Deliver object at 0x79ed98555310> Jun 04 13:04:46 2026 (26) IndividualDelivery to: cubewerk(a)gmail.com ==> /opt/mailman/core/var/logs/debug.log <== Jun 04 13:04:46 2026 (31) [VirginRunner] starting oneloop Jun 04 13:04:46 2026 (31) [VirginRunner] ending oneloop: 0 Jun 04 13:04:46 2026 (26) [OutgoingRunner] finishing filebase: 1780578286.711373+091038a49a00758fdd2ba5265714e2fa31ea4843 Jun 04 13:04:46 2026 (26) [OutgoingRunner] doing periodic Jun 04 13:04:46 2026 (26) [OutgoingRunner] committing transaction Jun 04 13:04:46 2026 (26) [OutgoingRunner] checking short circuit Jun 04 13:04:46 2026 (26) [OutgoingRunner] ending oneloop: 1 Jun 04 13:04:46 2026 (26) [OutgoingRunner] starting oneloop Jun 04 13:04:46 2026 (26) [OutgoingRunner] processing filebase: 1780578286.7329357+2ec378350ee99307adc287fc8727fb9120a385d3 Jun 04 13:04:46 2026 (26) [OutgoingRunner] processing onefile Jun 04 13:04:46 2026 (26) [outgoing] <function deliver at 0x79ed98b85d00>: <gxZS.-LyKCSHn9UWsyVepCakA9g(a)flTQyy2_BUC0KFtMliiieCkabFXP1SdNnP1xIyNQp-k.xz> ==> /opt/mailman/core/var/logs/smtp.log <== Jun 04 13:04:46 2026 (26) Using agent: <mailman.mta.deliver.Deliver object at 0x79ed98a43bf0> Jun 04 13:04:46 2026 (26) IndividualDelivery to: cubewerk(a)gmail.com If i restart the docker-core container, i see a single time the error "Cannot connect to SMTP server 172.17.0.1 on port 587". my config: [runner.retry] sleep_time: 10s [webservice] hostname: 172.18.0.2 port: 8001 admin_user: restadmin admin_pass: restpass configuration: /etc/gunicorn.cfg [mta] incoming: mailman.mta.postfix.LMTP outgoing: mailman.mta.deliver.deliver lmtp_host: 172.18.0.2 lmtp_port: 8024 smtp_host: 172.17.0.1 smtp_port: 587 smtp_user: smtp_pass: smtp_secure_mode: starttls smtp_verify_hostname: false smtp_verify_cert: false configuration: /etc/postfix-mailman.cfg [logging.smtp] level: debug [logging.error] level: debug [logging.debug] level: debug [archiver.mail_archive] enable: no configuration: /opt/mailman/mail_archive_dummy.cfg [archiver.hyperkitty] class: mailman_hyperkitty.Archiver enable: yes configuration: /etc/mailman-hyperkitty.cfg Any helps is greatly appreciated. thank you. Stefan

4 5

Kind of off-topic, but Mailman related
by Paul Tomblin May 30, 2026

May 30, 2026

I back up my server using "borg" to send it to a different server. I keep 7 dailies, 4 weeklies and 6 monthlies. When I used Mailman 2, my borg backup size stabilized and never seemed to grow much. But since switching to Mailman 3, my backup size has been growing, seemingly without bounds, even though the amount of disk space I'm using on the Mailman server isn't growing much. I suspect this might be because of the way it's storing stuff in PostgreSQL instead of in the file system is fooling borg's deduplication methodology. Does anybody else have any experience with borg and Mailman 3? Should I exclude postgreSQL from the backup and do a separate pg_dumpall? -- Paul Tomblin

2 3

Thank you for the tips a year ago! Please help me gather other use-cases
by Rodrigo Camacho May 29, 2026

May 29, 2026

Hello fellow mailing list users and enthusiasts. About a year ago I posted this thread: https://lists.mailman3.org/archives/list/mailman-users@mailman3.org/thread/… We are now using mailing lists as our only form of collaboration. Overall, the change has been super positive. We have become more productive and importantly our quality of life has increased. So much so, that I have built a site explaining some of the changes we have made to help other entrepreneurs get control of their lives by spending less money and time on specialized SaaS tools and sticking to standards. I have posted my particular use-case here: https://standardit.org/lanao.html I am posting this because there might be some interesting use cases amongst the users of this list. I aim at adding various use cases so that more business owners can identify themselves and think that this change is possible. If you think your use case could be of use, feel free to add here. I will include it in the site. Rodrigo succulentoats.com

1 0

Residual signature?
by Paul Tomblin May 28, 2026

May 28, 2026

One of my mailing lists that I converted over from my Mailman 2 instance doesn’t get used much. Well, something momentous happened and it got several messages overnight, and I noticed something odd about them. Every one has the signature “— \nAdministration:”. This looks like a fragment of the signature that Mailman 2 used to put on them, but I can’t figure out where it’s configured. There’s nothing in the list or domain template list that would do that. How can I stop it doing that? -- Paul Tomblin

3 7