Impossible to join mailing lists
Mailing lists seem to require filling captcha for signing up for them, but the captcha does not work. It is not displayed at all. This holds at least for systemd https://lists.freedesktop.org/mailman/listinfo/systemd-devel . I have been trying to subscribe for a week.
For this mailing list, it is impossible to sign up though mail, as it says "(Note that you really have to sign up with the web form below, signing up via the mail service is not available for spam fighting reasons.)"