I tried to configure policyd but seems not work.

http://policyd.sourceforge.net/readme.html

INSERT INTO throttle \
(_from,_count_max,_quota_max,_time_limit,_mail_size,_date,_priority)
VALUES ('@domain.com',      # domain                                   
          50,                # maximum messages per time unit
          250000000,         # size in bytes (250 megs) (maximum is 2gig)
          86400,             # time unit in seconds (1 day)
          10240000,          # maximum message size (10 meg)
          UNIX_TIMESTAMP(),  # current time
          5);                # priority of record