Hm, on second thought this might be a German regulation. German imprints definitely do need to contain a monitored email address (which somewhat hilariously is often [email protected] or [email protected]).

This used to be the only way of reaching my phone operator for a while (they had chat support, as well as a phone number, but ironically that one would only text-to-speech read out "helpful" FAQ articles and then hang up, only forwarding callers to a support agent if they know the secret incantation producing zero FAQ hits).