I sent an email to legal@, and they forwarded to firstname.lastname@example.org, and the OTRS queue replied.
And it had Gmail "?" mark which typically means it does not have SPF record or something like that. And a dig query confirmed that. Since wikidata.org actually sends some emails, it'd be better to have SPF record.
;; QUESTION SECTION: ;wikidata.org. IN TXT ;; ANSWER SECTION: wikidata.org. 599 IN TXT "google-site-verification=8Twc3OrOQ9oBq5C81ZCsPa3fRRJT1xdt5yDBvdnDtUQ" ;; Query time: 316 msec ;; SERVER: 18.104.22.168#53(22.214.171.124) ;; WHEN: Thu Nov 22 19:43:02 KST 2018