E.g. 1 https://docs.freebsd.org/cgi/getmsg.cgi?fetch=73914+0+archive/2020/freebsd-current/20200126.freebsd-current has "Next in thread" linking to https://docs.freebsd.org/cgi/mid.cgi?db=irt&id=CAMy0BGS15j9B0kdSjJ53JnWt2MJ+wWxZ6Aka3XsGkym=y4sFAQ@mail.gmail.com but this gives a huge list of unrelated messages. E.g. 2 https://docs.freebsd.org/cgi/getmsg.cgi?fetch=68400+0+archive/2020/freebsd-current/20200126.freebsd-current has "Next in thread" linking to https://docs.freebsd.org/cgi/mid.cgi?db=irt&id=20200122.155654.980180717476039692.yasu@utahime.org but this gives 'No answers found for: "20200122.155654.980180717476039692.yasu"'. docs.freebsd.org is an alias for wfe0.nyi.freebsd.org. wfe0.nyi.freebsd.org has address 96.47.72.84
There was an issue with the plus ("+") character in Message-Id value. This is fixed now.