Mine

defer message          = $sender_host_address is greylisted
      log_message      = greylisted.
      hosts            = !+relay_hosts
      domains          = +relay_domains
      !senders         = : postmaster@*
      set acl_m6       = $sender_host_address $sender_address $local_part@$domain
      set acl_m6       = ${readsocket{/var/run/greylistd/socket}{$acl_m6}{5s}{}{}}
      condition        = ${if eq {$acl_m6}{grey}{true}{false}}
      authenticated = *


Statistics since Mon Nov 27 11:45:38 2006 (41 minutes and 53 seconds ago)
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  0 items, matching   0 requests, are currently whitelisted
  0 items, matching   0 requests, are currently blacklisted
507 items, matching 508 requests, are currently greylisted