I am having a similar issue as Joe.
Our Mailman 3 server is running on Rocky Linux 9.5. It is deployed using a Python virtual environment.
(venv) [mailman@<server> shunt]$ mailman info GNU Mailman 3.3.9 (Tom Sawyer) Python 3.9.21 (main, Dec 5 2024, 00:00:00) [GCC 11.5.0 20240719 (Red Hat 11.5.0-2)] config file: /etc/mailman3/mailman.cfg <output trimmed>
Mailman 3.3.9 Postorius Version 1.3.10 HyperKitty version 1.3.9 Postfix = 3.5.25-1.el9 (may have some newer bits backported into it - RHEL way) Django version = 4.2.13
Output of the for loop Mark provided above shows that all the lists on the server have admin_immed_notify set to True.
Here is the activity from the mailman.log file when I send a message to the list and it gets held:
Apr 21 19:11:37 2025 (2564) sans-faculty: DMARC lookup for dgoldsmith@sans.org (_dmarc.sans.org) found p=reject in _dmarc.sans.org. = v=DMARC1; p=reject; rua=mailto:dmarc_agg@vali.email Apr 21 19:11:37 2025 (2564) HOLD: sans-faculty@mlm.sans.org post from dgoldsmith@sans.org held, message-id= <SJ0PR18MB5112D63A7D9F3851A4A6B0C0AEB82@SJ0PR18MB5112.namprd18.prod.outlook.com>: The message comes from a moderated member
No further activity indicating it sends (or attempts to) a notice to the list admins/mods about a held message.