Eggert Ehmke writes:
When I look into mailman/mm/var/templates the directory is empty. Nevertheless, the templates I create in Postorius seem to be stored (where?),
That is expected when you create templates in Postorius, because they are stored in the RDBMS (eg, PostgreSQL).
they just do not work.
My first guess would be that there's a language mismatch. You need to create a variant template for each language that is used. I'm not sure offhand how the system chooses the language for stored templates vs the language for templates used for messages (I suspect the used template is the one for the list's default language), but an incomplete set of variant templates and a mismatch between the language the variant template was created in and the default language of the list is what I would guess.
Steve