The list at parabola.nu lack a Reply-to: header this causes people using the reply option to reply off list by default.

This causes confusion for people that are not used to listserves and frustration for the people that get replied to directly.

Mailman has the option to manage the Reply-to header. See: https://www.gnu.org/software/mailman/mailman-admin/node11.html

Someone should tweak this when the get a chance to set the default to reply-goes-to list.