Comment 4 for bug 1917336

Thanks for the bug report.

This happens because of how systemd handles /var/run/. If you look at the directory, you will see that it is actually a symlink to /run/. This directory is populated on every boot. There are a few ways that packages can choose in order to create directories under this directory; mailman chooses to use a tmpfiles.d configuration file.

If you look at /usr/lib/tmpfiles.d/mailman.conf you will see this:

# path mode uid gid
d /run/mailman 0755 list list
d /run/lock/mailman 2775 root list

In order to achieve what you want, you need to change the "uid" field in the first line. The recommended way to change this file is to actually create a copy of it under /etc/tmpfiles.d/, so that you don't change the original file from the package (which could get overwritten during an update).

To summarize, your file /etc/tmpfiles.d/mailman.conf should look like:

# path mode uid gid
d /run/mailman 0755 www-data list
d /run/lock/mailman 2775 root list

I am closing this bug as Invalid because it is a local configuration question rather than a problem, but please let us know if the steps above don't work for you. Thanks!