Dear Maintainer,

Thank you for all your work on the mailman3 package. I have just started to try to install this and migrating a mailman2 residual configuration.

I have been unable to get mailman to receive mail from Exim4. While exim4 is selecting the correct router and transport I am getting:

2021-10-21 22:29:38 1mdfd3-005vLS-T4 == roleplay@lists.piglets.com R=mailman3_router T=mailman3_transport defer (111): Connection refused

on all emails I am trying to send as tests to the lists.
----- Exim Config -----

My exim4 transport is as follows:

# /etc/exim4/conf.d/transport/55_mm3_transport
mailman3_transport:
  driver = smtp
  protocol = lmtp
  allow_localhost
  hosts = localhost
  port = MM3_LMTP_PORT
  rcpt_include_affixes = true

and the MM3_LMTP_PORT is defined here:

# /etc/exim4/conf.d/main/25_mm3_macros
# The colon-separated list of domains served by Mailman.
domainlist mm_domains=lists.piglets.com

MM3_LMTP_PORT=8024

# MM3_HOME must be set to mailman's var directory, wherever it is
# according to your installation.
MM3_HOME=/var/lib/mailman3
MM3_UID=list
MM3_GID=list

################################################################
# The configuration below is boilerplate:
# you should not need to change it.

# The path to the list receipt (used as the required file when
# matching list addresses)
MM3_LISTCHK=MM3_HOME/lists/${local_part}.${domain}

----- mta in mailman.cfg -----

The [mta] stanza of my mailman.cfg files is as below

[mta]
# The class defining the interface to the incoming mail transport agent.
incoming: mailman.mta.exim4.LMTP
#incoming: mailman.mta.postfix.LMTP

# The callable implementing delivery to the outgoing mail transport agent.
# This must accept three arguments, the mailing list, the message, and the
# message metadata dictionary.
outgoing: mailman.mta.deliver.deliver

# How to connect to the outgoing MTA.  If smtp_user and smtp_pass is given,
# then Mailman will attempt to log into the MTA when making a new connection.
smtp_host: 127.0.0.1
smtp_port: 25
smtp_user:
smtp_pass:

# Where the LMTP server listens for connections.  Use 127.0.0.1 instead of
# localhost for Postfix integration, because Postfix only consults DNS
# (e.g. not /etc/hosts).
lmtp_host: localhost
lmtp_port: 8024

# Where can we find the mail server specific configuration file?  The path can
# be either a file system path or a Python import path.  If the value starts
# with python: then it is a Python import path, otherwise it is a file system
# path.  File system paths must be absolute since no guarantees are made about
# the current working directory.  Python paths should not include the trailing
# .cfg, which the file must end with.
configuration: python:mailman.config.exim4
#configuration: python:mailman.config.postfix

-----

I have tried restarting all the relevant services. Telnet shows the runner to be listening

root@gondolin:~# telnet localhost 8024
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
220 gondolin.piglets.org GNU Mailman LMTP runner 2.0

But for some reason all email inbound is being rejected as connection refused. I have probably made an elementary error, but I'm not sure where if so, so apologies in advance.

Kind regards,

CT.

PS. I also ran into the issue #996560 of broken web links and fixed it with the same workaround

Dear Maintainer,

I have fixed my issue. I finally realised this morning all my tests that the LMTP runner was running were on IPv4, and sure enough

telnet ::1 8024

showed “Connection refused”

There are no firewall rules that seem to be relevant, so I guess mailman3 is not reachable on IPv6 maybe but I haven’t investigated further.

In the meantime I have changed the transport for exim4 to be as follows:

# /etc/exim4/conf.d/transport/55_mm3_transport
mailman3_transport:
  driver = smtp
  protocol = lmtp
  allow_localhost
  # hosts = localhost
  # There seems to be a problem with the host being used in ipv6? Let's try this
  hosts = 127.0.0.1
  port = MM3_LMTP_PORT
  rcpt_include_affixes = true

Should it be working over IPv6? And if not, is this worth adding to README.Debian?

Many thanks for your work and apologies for the issue!

Kind regards,

CT.

Colin Turner wrote:

The LMTP runner listens on 127.0.0.1:8024 by default however this can be changed in the mailman.cfg

https://docs.mailman3.org/projects/mailman/en/latest/src/mailman/config/docs/config.html

However, I think the issue you ran into was Exim specific and not related to Mailman LMTP runner listening on ::1. I had a similar issue when upgrading to Bullseye and on the old host Mailman LMTP runner was still only listening on 127.0.0.1:8024. Based on this doc:

https://www.exim.org/exim-html-current/doc/html/spec_html/ch-the_dnslookup_router.html

I made a slightly different edit to the transport:

mailman_transport:
  debug_print = "Email for mailman"
  driver = smtp
  protocol = lmtp
  allow_localhost
  gethostbyname
  hosts = localhost
  port = 8024
  rcpt_include_affixes = true

I never tried to make Mailman LMTP listen on IPV6.

Thanks.
Andrew.