policy_quota_auth_limit()
  A policy quota for authorized users.
  
  Limit number of emails from an authorized user.
  Do not use multiple of policy_quota_auth_limit tests in one policy service,
  use arrays for interval, max_conn, max_rcpt instead.
  
  Usage: policy_quota_auth_limit(interval, max_conn, max_rcpt)
  
  Where: interval - counting interval in seconds
         max_conn - maximum number of connections to server
         max_rcpt - maximum number of recipients
  
  Example: policy_quota_auth_limit(300, 10, 150)
  
  Postfix configuration example:
    smtpd_data_restrictions =  check_policy_service inet:127.0.0.1:30
  
  SQL command, which can help you to set proper parameters.
  Change 3600 with your current interval settings.
    SELECT username, sum(1) AS count, sum(recipient_count) AS rcpt,
           from_unixtime(timestamp/1000) AS time, group_concat(DISTINCT ip)
    FROM policy_quota
    GROUP BY username, floor(timestamp/1000/3600)
    ORDER BY count DESC, rcpt DESC;
  
  New in version 1.3.0.