As a followup to CFB, from my other account.
The REFCARD gives this as one of the commands you could send to  listserv@lists.oberon.ch

SEArch       listname word1 <word2 <...>>      Search list archives
       or:  word1 <word2 <...>> IN listname
            FROM date1                        -> From this date
                 TODAY                        -> From today
                 TODAY-7                      -> In the last 7 days
            TO   date2                        -> To this date
            WHERE
              SUBJECT CONTAINS xxxx           -> Only this subject
            AND/OR
              SENDER  CONTAINS xxxx           -> Only this author
                                              Complex boolean operations are
                                              supported, see database guide

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