Chasing the mailman

I recently tried to set up a mailing list with [Mailman][]. The initial set-up was very easy, with all the tools (m web host provides cPanel) giving simple and clear instructions. However, the list didn’t work as expected. The list’s administrator interface seemed to allow me to subscribe new memebers, but when I posted to the list from any of the subscribed email addreses, none of my messages would be distributed. The messages also didn’t show in either the archive or the moderator section of the admin interface.

I got in touch with my host’s live chat support, because debugging an issue like this seemed to require more effort than I was willing to put in. I feared I would need to learn more about Mailman, cPanel and maybe WHM. The customer service agent was helpful. They fixed the issue. I tried to find out about the issue in case something similar happens again. I was told that a port number was wrongly specified in Mailman’s configuration. It’s changable in “/usr/local/cpanel/3rdparty/mailman/Mailman/Defaults.py”, and should have been:

SMTP_PORT = 125

Hopefully this is enough to fix similar issues in the future.

I’m mildly concerned that it wont be. Mailman is a default part of my hosting package, which I assume is generated by WHM. My hosting provider configures WHM to produce new virtual hosts of a particular form (cPanel, mysql, apache, php, softaculous etc). The fact that the port number for a fairly standard service is misconfigured is troubling.