diff --git a/Lib/mailbox.py b/Lib/mailbox.py
index bb115e1..b72128b 100755
--- a/Lib/mailbox.py
+++ b/Lib/mailbox.py
@@ -15,7 +15,10 @@
 import rfc822
 import StringIO
 try:
-    import fnctl
+    if sys.platform == 'os2emx':
+        # OS/2 EMX fcntl() not adequate
+        raise ImportError
+    import fcntl
 except ImportError:
     fcntl = None
 
@@ -565,7 +568,8 @@
         try:
             os.rename(new_file.name, self._path)
         except OSError, e:
-            if e.errno == errno.EEXIST:
+            if e.errno == errno.EEXIST or \
+              (os.name == 'os2' and e.errno == errno.EACCES):
                 os.remove(self._path)
                 os.rename(new_file.name, self._path)
             else:
@@ -1030,6 +1034,9 @@
                         if hasattr(os, 'link'):
                             os.link(os.path.join(self._path, str(key)),
                                     os.path.join(self._path, str(prev + 1)))
+                            if sys.platform == 'os2emx':
+                                # cannot unlink an open file on OS/2
+                                f.close()
                             os.unlink(os.path.join(self._path, str(key)))
                         else:
                             f.close()
@@ -1798,26 +1805,18 @@
 
 
 def _lock_file(f, dotlock=True):
-    """Lock file f using lockf, flock, and dot locking."""
+    """Lock file f using lockf and dot locking."""
     dotlock_done = False
     try:
         if fcntl:
             try:
                 fcntl.lockf(f, fcntl.LOCK_EX | fcntl.LOCK_NB)
             except IOError, e:
-                if e.errno == errno.EAGAIN:
+                if e.errno in (errno.EAGAIN, errno.EACCES):
                     raise ExternalClashError('lockf: lock unavailable: %s' %
                                              f.name)
                 else:
                     raise
-            try:
-                fcntl.flock(f, fcntl.LOCK_EX | fcntl.LOCK_NB)
-            except IOError, e:
-                if e.errno == errno.EWOULDBLOCK:
-                    raise ExternalClashError('flock: lock unavailable: %s' %
-                                             f.name)
-                else:
-                    raise
         if dotlock:
             try:
                 pre_lock = _create_temporary(f.name + '.lock')
@@ -1836,7 +1835,8 @@
                     os.rename(pre_lock.name, f.name + '.lock')
                     dotlock_done = True
             except OSError, e:
-                if e.errno == errno.EEXIST:
+                if e.errno == errno.EEXIST or \
+                  (os.name == 'os2' and e.errno == errno.EACCES):
                     os.remove(pre_lock.name)
                     raise ExternalClashError('dot lock unavailable: %s' %
                                              f.name)
@@ -1845,16 +1845,14 @@
     except:
         if fcntl:
             fcntl.lockf(f, fcntl.LOCK_UN)
-            fcntl.flock(f, fcntl.LOCK_UN)
         if dotlock_done:
             os.remove(f.name + '.lock')
         raise
 
 def _unlock_file(f):
-    """Unlock file f using lockf, flock, and dot locking."""
+    """Unlock file f using lockf and dot locking."""
     if fcntl:
         fcntl.lockf(f, fcntl.LOCK_UN)
-        fcntl.flock(f, fcntl.LOCK_UN)
     if os.path.exists(f.name + '.lock'):
         os.remove(f.name + '.lock')