process-hold.py

#!/usr/bin/env python

import os
import sys
import time
import datetime

expanduser = os.path.expanduser
expandvars = os.path.expandvars

def expand( name ): # handle $HOME/pathname or ~user/pathname
  return expandvars( expanduser( name ))

if os.name in ( 'posix', 'dos' ):
  DO_NOT_INCLUDE = ( '.', '..' ) # don't include these for dos & posix
else:
  print "Unknown OS,", os.name, "exiting"
  sys.exit(1);

def find( *paths ):
  list = []
  for pathname in paths:
    os.path.walk( expand(pathname), append, list )
  return list

def append( list, dirname, filelist ):
  for filename in filelist:
    if filename not in DO_NOT_INCLUDE:
      filename = os.path.join( dirname, filename )
      if not os.path.islink( filename ):
        list.append( filename )


if __name__ == "__main__":
  threshold = 100
  release = 20
  sleep = 1
  
  while True:
    hold_files = []
    os.path.walk(expand("/var/spool/postfix/hold"), append, hold_files)
    num_hold = len(hold_files)

    active_files = []
    os.path.walk(expand("/var/spool/postfix/active"), append, active_files)
    num_active = len(active_files)

    deferred_files = []
    os.path.walk(expand("/var/spool/postfix/deferred"), append, deferred_files)
    num_deferred = len(deferred_files)

    print datetime.datetime.now(), "hold", num_hold, "active", num_active, "deferred", num_deferred
    if num_hold > 0:
      if num_active + num_deferred < threshold:
        process_files = hold_files[0:min(release, num_hold)]
        #print "Process more mail", process_files
        for file in process_files:
          cmd = "postsuper -H " + os.path.basename(file)
          os.system(cmd)
          print cmd
        os.system("postqueue -f")
      print "Waiting for awhile to process -- sleeping", sleep, "minutes"
      time.sleep(60 * sleep)
    else:
      print "No more hold files"
      sys.exit(0);