Here is where it describes it blacklisted

      3.3 RCVD_IN_PBL            RBL: Received via a relay in Spamhaus
     PBL
                                 [37.120.193.122 listed in
     [1]zen.spamhaus.org]
      1.3 RCVD_IN_BL_SPAMCOP_NET RBL: Received via a relay in
                                 [2]bl.spamcop.net
                  [Blocked - see
     <[3]https://www.spamcop.net/bl.shtml?37.120.193.122>]

References

   1. http://zen.spamhaus.org/
   2. http://bl.spamcop.net/
   3. https://www.spamcop.net/bl.shtml?37.120.193.122