diff --git a/wallace/__init__.py b/wallace/__init__.py
index 5a2ffbd..6e79d97 100644
--- a/wallace/__init__.py
+++ b/wallace/__init__.py
@@ -1,542 +1,549 @@
 # -*- coding: utf-8 -*-
 # Copyright 2010-2013 Kolab Systems AG (http://www.kolabsys.com)
 #
 # Jeroen van Meeuwen (Kolab Systems) <vanmeeuwen a kolabsys.com>
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 3 of the License, or
 # (at your option) any later version.
 
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 
 import asyncore
 from distutils import version
 import grp
 import multiprocessing
 import os
 import pwd
 import traceback
 from smtpd import SMTPChannel
 import socket
 import struct
 import sys
 import tempfile
 from threading import _Timer
 import time
 import traceback
 
 import pykolab
 from pykolab import utils
 from pykolab.translate import _
 
 log = pykolab.getLogger('pykolab.wallace')
 conf = pykolab.getConf()
 
 from modules import cb_action_ACCEPT
 
 def pickup_message(filepath, *args, **kw):
     wallace_modules = args[0]
     if kw.has_key('module'):
 
         # Cause the previous modules to be skipped
         wallace_modules = wallace_modules[(wallace_modules.index(kw['module'])+1):]
 
         log.debug(_("Wallace modules: %r") % (wallace_modules), level=8)
 
         # Execute the module
         if kw.has_key('stage'):
             modules.execute(kw['module'], filepath, stage=kw['stage'])
         else:
             modules.execute(kw['module'], filepath)
 
     # After all modules are executed, continue with a call to
     # accept the message and re-inject in to Postfix.
     continue_with_accept = True
 
     for module in wallace_modules:
         try:
             result_filepath = modules.execute(module, filepath)
         except:
             log.error(_("Module %s.execute() failed on message %r with error: %s" % (module, filepath, traceback.format_exc())))
             result_filepath = False
 
         if not result_filepath == None and not result_filepath == False:
             filepath = result_filepath
         else:
             # A module has returned False or None
             continue_with_accept = False
             # The message very likely has been consumed by the module that returned False
             if not os.path.isfile(filepath):
                 break
 
     if continue_with_accept:
         cb_action_ACCEPT('wallace', filepath)
 
 def modules_heartbeat(wallace_modules):
     lastrun = 0
 
     while True:
         try:
             for module in wallace_modules:
                 try:
                     modules.heartbeat(module, lastrun)
                 except:
                     log.error(_("Module %s.heartbeat() failed with error: %s" % (module, traceback.format_exc())))
 
             lastrun = int(time.time())
             time.sleep(60)
         except (SystemExit, KeyboardInterrupt), e:
             log.info("Terminating heartbeat process")
             break
 
 def worker_process(*args, **kw):
     log.debug(_("Worker process %s initializing") % (multiprocessing.current_process().name), level=1)
 
 class Timer(_Timer):
     def run(self):
         while True:
             while not self.finished.is_set():
                 self.finished.wait(self.interval)
                 self.function(*self.args, **self.kwargs)
 
             self.finished.set()
 
 class WallaceDaemon(object):
     def __init__(self):
         self.current_connections = 0
         self.max_connections = 24
         self.pool = None
 
         daemon_group = conf.add_cli_parser_option_group(_("Daemon Options"))
 
         daemon_group.add_option(
                 "--fork",
                 dest    = "fork_mode",
                 action  = "store_true",
                 default = False,
                 help    = _("Fork to the background.")
             )
 
         daemon_group.add_option(
                 "-b", "--bind",
                 dest    = "wallace_bind_address",
                 action  = "store",
                 default = "localhost",
                 help    = _("Bind address for Wallace.")
             )
 
         daemon_group.add_option(
                 "-g",
                 "--group",
                 dest    = "process_groupname",
                 action  = "store",
                 default = "kolab",
                 help    = _("Run as group GROUPNAME"),
                 metavar = "GROUPNAME"
             )
 
         daemon_group.add_option(
                 "--threads",
                 dest    = "max_threads",
                 action  = "store",
                 default = 4,
                 type    = int,
                 help    = _("Number of threads to use.")
             )
 
         daemon_group.add_option(
                 "-p", "--pid-file",
                 dest    = "pidfile",
                 action  = "store",
                 default = "/var/run/wallaced/wallaced.pid",
                 help    = _("Path to the PID file to use.")
             )
 
         daemon_group.add_option(
                 "--port",
                 dest    = "wallace_port",
                 action  = "store",
                 default = 10026,
                 type    = int,
                 help    = _("Port that Wallace is supposed to use.")
             )
 
         daemon_group.add_option(
                 "-u",
                 "--user",
                 dest    = "process_username",
                 action  = "store",
                 default = "kolab",
                 help    = _("Run as user USERNAME"),
                 metavar = "USERNAME"
             )
 
         conf.finalize_conf()
 
         utils.ensure_directory(
                 os.path.dirname(conf.pidfile),
                 conf.process_username,
                 conf.process_groupname
             )
 
         import modules
         modules.__init__()
 
         self.modules = conf.get_list('wallace', 'modules')
         if self.modules == None:
             self.modules = []
 
     def do_wallace(self):
         if version.StrictVersion(sys.version[:3]) >= version.StrictVersion("2.7"):
             self.pool = multiprocessing.Pool(conf.max_threads, worker_process, (), 1)
         else:
             self.pool = multiprocessing.Pool(conf.max_threads, worker_process, ())
 
         self.pickup_spool_messages(sync=True)
 
         s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
         s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
 
         bound = False
         shutdown = False
         while not bound:
             try:
                 if shutdown:
                     s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
                     s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
 
                 s.bind((conf.wallace_bind_address, conf.wallace_port))
                 bound = True
             except Exception, e:
                 log.warning(
                         _("Could not bind to socket on port %d on bind " + \
                             "address %s") % (
                                 conf.wallace_port,
                                 conf.wallace_bind_address
                             )
                     )
 
                 while not shutdown:
                     try:
                         s.shutdown(socket.SHUT_RDWR)
                         shutdown = True
                     except Exception, e:
                         log.warning(_("Could not shut down socket"))
                         time.sleep(1)
 
                 s.close()
 
                 time.sleep(1)
 
         s.listen(5)
 
         self.timer = Timer(180, self.pickup_spool_messages)
         self.timer.start()
 
         # start background process to run periodic jobs in active modules
         self.heartbeat = multiprocessing.Process(target=modules_heartbeat, args=[self.modules])
         self.heartbeat.daemon = True
         self.heartbeat.start()
 
         try:
             while 1:
                 while self.current_connections >= self.max_connections:
                     time.sleep(0.5)
 
                 pair = s.accept()
                 log.info(_("Accepted connection"))
                 if not pair == None:
                     self.current_connections += 1
                     connection, address = pair
                     channel = SMTPChannel(self, connection, address)
                     asyncore.loop()
 
         except Exception, errmsg:
             traceback.print_exc()
             s.shutdown(1)
             s.close()
 
         # shut down hearbeat process
         self.heartbeat.terminate()
 
     def data_header(self, mailfrom, rcpttos):
         COMMASPACE = ', '
         return "X-Kolab-From: " + mailfrom + "\r\n" + \
                 "X-Kolab-To: " + COMMASPACE.join(rcpttos) + "\r\n"
 
     def pickup_spool_messages(self, sync=False):
         # Mind you to include the trailing slash
         pickup_path = '/var/spool/pykolab/wallace/'
 
         messages = []
         for root, directory, files in os.walk(pickup_path):
             for filename in files:
                 messages.append((root, filename))
 
 
         for root, filename in messages:
             filepath = os.path.join(root, filename)
 
             try:
+                # ignore calls on too young files
                 if os.stat(filepath).st_mtime + 150 > time.time():
-                    log.debug("Skipping %s" % (filepath), level=8)
+                    log.debug("File not more than 150s old. Skipping %s" % (filepath), level=8)
                     continue
 
-            except:
+                # ignore calls on lock files
+                if '/locks/' in filepath:
+                    log.debug("File is in locks directory. Skipping %s" % (filepath), level=8)
+                    continue
+
+            except Exception, errmsg:
+                log.error("Error: %s. Skipping %s" % (errmsg, filepath))
                 continue
 
             if not root == pickup_path:
                 module = os.path.dirname(root).replace(pickup_path, '')
 
                 # Compare uppercase status (specifically, DEFER) with
                 # lowercase (plugin names).
                 #
                 # The messages in DEFER are supposed to be picked up by
                 # another thread, whereas the messages in other directories
                 # are pending being handled by their respective plugins.
                 #
                 # TODO: Handle messages in spool directories for which a
                 # plugin had been enabled, but is not enabled any longer.
                 #
 
                 if module.lower() == "defer":
                     # Wallace was unable to deliver to re-injection smtpd.
                     # Skip it, another thread is picking up the deferred
                     # messages.
                     continue
 
                 stage = root.replace(pickup_path, '').split('/')
 
                 if len(stage) < 2:
                     stage = None
                 else:
                     stage = stage[1]
 
                 if stage.lower() == "hold":
                     continue
 
                 # Do not handle messages in a defer state.
                 if stage.lower() == "defer":
                     continue
 
                 self.current_connections += 1
 
                 if sync:
                     pickup_message(filepath, self.modules, module=module, stage=stage)
                 else:
                     self.pool.apply_async(
                         pickup_message,
                         (
                             filepath,
                             (self.modules),
                             {'module': module, 'stage': stage}
                         )
                     )
 
                 self.current_connections -= 1
 
                 continue
 
             self.current_connections += 1
 
             if sync:
                 pickup_message(filepath, self.modules)
             else:
                 self.pool.apply_async(pickup_message, (filepath, (self.modules)))
 
             self.current_connections -= 1
 
     def process_message(self, peer, mailfrom, rcpttos, data):
         """
             We have retrieved the message. This should be as fast as possible,
             and not ever block.
         """
 
         header = self.data_header(mailfrom, rcpttos)
 
         (fp, filename) = tempfile.mkstemp(dir="/var/spool/pykolab/wallace/")
 
         # @TODO: and add line separator (\n or \r\n?)
         # we should make sure there's only one line separator between
         # kolab headers and the original message (data)
         os.write(fp, header);
         os.write(fp, data)
         os.close(fp)
 
         self.pool.apply_async(pickup_message, (filename, (self.modules)))
 
         self.current_connections -= 1
 
         return "250 OK Message %s queued" % (filename)
 
     def reload_config(self, *args, **kw):
         pass
 
     def remove_pid(self, *args, **kw):
         if os.access(conf.pidfile, os.R_OK):
             os.remove(conf.pidfile)
 
         if self.pool is not None:
             self.pool.close()
             self.pool.join()
 
         raise SystemExit
 
     def run(self):
         """
             Run the Wallace daemon.
         """
 
         exitcode = 0
 
         try:
             try:
                 (ruid, euid, suid) = os.getresuid()
                 (rgid, egid, sgid) = os.getresgid()
             except AttributeError, errmsg:
                 ruid = os.getuid()
                 rgid = os.getgid()
 
             if ruid == 0:
                 # Means we can setreuid() / setregid() / setgroups()
                 if rgid == 0:
                     # Get group entry details
                     try:
                         (
                                 group_name,
                                 group_password,
                                 group_gid,
                                 group_members
                             ) = grp.getgrnam(conf.process_groupname)
 
                     except KeyError:
                         print >> sys.stderr, _("Group %s does not exist") % (
                                 conf.process_groupname
                             )
 
                         sys.exit(1)
 
                     # Set real and effective group if not the same as current.
                     if not group_gid == rgid:
                         log.debug(
                                 _("Switching real and effective group id to %d") % (
                                         group_gid
                                     ),
                                 level=8
                             )
 
                         os.setregid(group_gid, group_gid)
 
                 if ruid == 0:
                     # Means we haven't switched yet.
                     try:
                         (
                                 user_name,
                                 user_password,
                                 user_uid,
                                 user_gid,
                                 user_gecos,
                                 user_homedir,
                                 user_shell
                             ) = pwd.getpwnam(conf.process_username)
 
                     except KeyError:
                         print >> sys.stderr, _("User %s does not exist") % (
                                 conf.process_username
                             )
 
                         sys.exit(1)
 
 
                     # Set real and effective user if not the same as current.
                     if not user_uid == ruid:
                         log.debug(
                                 _("Switching real and effective user id to %d") % (
                                         user_uid
                                     ),
                                 level=8
                             )
 
                         os.setreuid(user_uid, user_uid)
 
         except:
             log.error(_("Could not change real and effective uid and/or gid"))
 
         try:
             pid = os.getpid()
 
             if conf.fork_mode:
                 pid = os.fork()
 
             if pid > 0 and not conf.fork_mode:
                 self.do_wallace()
 
             elif pid > 0:
                 sys.exit(0)
 
             else:
                 # Give up the session, all control,
                 # all open file descriptors, see #5151
                 os.chdir("/")
                 os.umask(0)
                 os.setsid()
 
                 pid = os.fork()
 
                 if pid > 0:
                     sys.exit(0)
 
                 sys.stderr.flush()
                 sys.stdout.flush()
 
                 os.close(0)
                 os.close(1)
                 os.close(2)
 
                 log.remove_stdout_handler()
                 self.set_signal_handlers()
                 self.write_pid()
                 self.do_wallace()
 
         except SystemExit, e:
             exitcode = e
         except KeyboardInterrupt:
             exitcode = 1
             log.info(_("Interrupted by user"))
         except AttributeError, e:
             exitcode = 1
             traceback.print_exc()
             print >> sys.stderr, _("Traceback occurred, please report a bug at https://issues.kolab.org")
 
         except TypeError, e:
             exitcode = 1
             traceback.print_exc()
             log.error(_("Type Error: %s") % e)
         except:
             exitcode = 2
             traceback.print_exc()
             print >> sys.stderr, _("Traceback occurred, please report a bug at https://issues.kolab.org")
 
         sys.exit(exitcode)
 
     def set_signal_handlers(self):
         import signal
         signal.signal(signal.SIGHUP, self.reload_config)
         signal.signal(signal.SIGTERM, self.remove_pid)
 
     def write_pid(self):
         pid = os.getpid()
         if os.access(os.path.dirname(conf.pidfile), os.W_OK):
             fp = open(conf.pidfile,'w')
             fp.write("%d\n" % (pid))
             fp.close()
         else:
             print >> sys.stderr, _("Could not write pid file %s") % (conf.pidfile)