[Mailman-Users] mailman uses wrong encoding, /etc/mailman/[language] not generated

[Johannes Rohr]

Dear all,

we have recently migrated from a server with Ubuntu 14.4 to one using
Ubuntu's current LTS.

The default language for most mailing lists is German. Since the migration,
mailman serves all pages and mail notifications in latin-1 instead of
utf-8, which the header still decleares the content to be UTF-8, which
leads to broken display, see eg
https://lists.uferwerk.org/cgi-bin/mailman/listinfo/

I noticed that the subdirectory for the English templates /etc/mailman/en
exists, but there is no /etc/mailman/de

On Debian/Ubuntu, /var/lib/mailman/Templates  is a symlink to /etc/mailman,
which by default is owned by root:root. I changed that to root:list and
restarted mailman, in the hope that /etc/mailman/de would eventually be
generated, but it wasn't.

What is the mechanism, by which the templates directory for the respective
language is generated? Could this be a permission issue, and could the
mismatch between the charset declared in the header of the message or
website and the actual charset in the content be somehow related to that?

Thanks in advance for any suggestion,

Johannes