Mailman 3 January 2026 - Mailman-Users

mailman-loop sending mail to undesirable address
by Macs R We April 9, 2026

April 9, 2026

I tried posting this twice at the website and it appears to blackholed both times, don’t know whether it’s a new-user moderating thing or what. So apologies if this is a duplicate Hopefully, this is simple. I know nothing about the innards of Mailman -- I've been just using it as a black box for a decade and it's been working fine. Today, in the process of handling a subscriber's non-delivery complaint, I came across this error message in WHM's Mail Delivery Reports: From Address: mailman-loop(a)server.wickenburg.us Sender: Sent Time: Feb 22, 2025, 6:48:18 PM Sender Host: server.wickenburg.us Sender IP: 127.0.0.1 Authentication: unauthorized Spam Score: 0 Recipient: root(a)cloud-ci.unifiedlayer.com Delivered To: Delivery User: Delivery Domain: cloud-ci.unifiedlayer.com Router: reject Transport: **rejected** Out Time: Feb 22, 2025, 6:48:18 PM ID: 1tm16p-00000000BOG-aS00 Delivery Host: server.wickenburg.us Delivery IP: 127.0.0.1 Size: 0 bytes Result: The mail server could not deliver mail to root(a)cloud-ci.unifiedlayer.com. The account or domain may not exist, they may be blacklisted, or missing the proper dns entries. The recipient identified is not anything I ever set up. "unifiedlayer" belongs to my hosting provider, so this may be some sort of default or unset value. I've scoured the Mailman configuration screens for anything resembling this, or any field I should have provided but left blank, and I'm buffaloed. Where is Mailman getting this value from, and how to I change it to something more useful?

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Sync_members Error (mailman 2)
by jerry.barnabee＠gmail.com Jan. 14, 2026

Jan. 14, 2026

Any idea what is causing this error ? root@server bin]# /usr/local/cpanel/3rdparty/mailman/bin/sync_members -f /home/webapps/snippets/Backups/RefreshMailingListDaily.txt executiveboard_xxxx.xxxx Traceback (most recent call last): File "/usr/local/cpanel/3rdparty/mailman/bin/sync_members", line 291, in <module> main() File "/usr/local/cpanel/3rdparty/mailman/bin/sync_members", line 240, in main elif not matches.has_key(laddr): AttributeError: 'dict' object has no attribute 'has_key'

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Digest emails to Gmail bouncing
by Brie Yoder Jan. 6, 2026

Jan. 6, 2026

[Using MM 2.1.39 hosted at dreamhost.com] Starting Dec 27, the Mailman list I admin started getting bounces to Gmail accounts, but only for digest messages - the individual messages have been going through without (apparent) problem. Sample bounce error: <redacted(a)gmail.com>: host gmail-smtp-in.l.google.com[192.178.163.27] said: 550-5.7.1 [69.163.136.29 12] Gmail has detected that this message is likely 550-5.7.1 unsolicited mail. To reduce the amount of spam sent to Gmail, this 550-5.7.1 message has been blocked. For more information, go to 550 5.7.1 https://support.google.com/mail/?p=UnsolicitedMessageError 41be03b00d2f7-c1e7d1d12a2si62798268a12.385 - gsmtp (in reply to end of DATA command) Has anyone else experienced this? The list has been around for ~10 years and this just started happening a week ago. It is very large - 7200 total members; over half are Gmail accounts. Trying to get help from Dreamhost has been extremely frustrating - I get a response from a new tech each time who can’t be bothered to read the case history and says, Oh this is a spam problem, so we can’t help 🙄 Going into the Google postmaster tools, I see they say DKIM is failing for the domain at issue. When I run a DKIM checker<https://mxtoolbox.com/SuperTool.aspx> on the domain, everything is fine. Looking in a digest email header, there are no DKIM-Signature: headers, but there are ARC-Seal: and ARC-Message-Signature: headers. (Is this expected or is this a bug?) This page<https://www.suped.com/guides/dkim/a-practical-guide-to-dkim-selector-name-e…> says to look at the s= value in the DKIM-Signature: header for what the proper DKIM selector should be for my domain, in an email sent from the domain. Should I be checking the s= value in the ARC-Message-Signature: header of a digest email to confirm a valid DKIM selector? Something else? -Brie

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Migrating from Mailman to Groups.IO, a few questions
by Jayson Smith Jan. 4, 2026

Jan. 4, 2026

Hi, I'm strongly considering migrating my two remaining Mailman lists to Groups.IO. The primary reason for this is since I'm still running Mailman version 2, and I need to spin down that installation so it won't be an issue when I upgrade to a newer Debian version which no longer has Python 2. I have two questions. 1. Has anyone written a custom version of the list_members script which exports list members in a format compatible with Groups.IO's direct add feature? In short, Groups.IO allows you to add "digest" or "nomail" after an Email address to pre-select that delivery option for that member. I'd love a way to have that work automatically done. 2. Is there any way within Mailman to send what Groups.IO would call a "Special Notice?" That is, a message which will go to all members immediately, even those on digest or nomail? I'm going to want an easy way to announce the impending move in such a way that every member will receive the message immediately. Thanks, Jayson

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