diff --git a/Lib/mailbox.py b/Lib/mailbox.py
index 8d1df4b..2293a6c 100755
--- a/Lib/mailbox.py
+++ b/Lib/mailbox.py
@@ -258,7 +258,7 @@
                 os.remove(tmp_file.name)
             else:
                 os.rename(tmp_file.name, dest)
-        except OSError, e:
+        except OSError as e:
             os.remove(tmp_file.name)
             if e.errno == errno.EEXIST:
                 raise ExternalClashError('Name clash with existing message: %s'
@@ -280,7 +280,7 @@
             self.remove(key)
         except KeyError:
             pass
-        except OSError, e:
+        except OSError as e:
             if e.errno != errno.ENOENT:
                 raise
 
@@ -437,12 +437,12 @@
         path = os.path.join(self._path, 'tmp', uniq)
         try:
             os.stat(path)
-        except OSError, e:
+        except OSError as e:
             if e.errno == errno.ENOENT:
                 Maildir._count += 1
                 try:
                     return _create_carefully(path)
-                except OSError, e:
+                except OSError as e:
                     if e.errno != errno.EEXIST:
                         raise
             else:
@@ -495,7 +495,7 @@
         Mailbox.__init__(self, path, factory, create)
         try:
             f = open(self._path, 'rb+')
-        except IOError, e:
+        except IOError as e:
             if e.errno == errno.ENOENT:
                 if create:
                     f = open(self._path, 'wb+')
@@ -605,7 +605,7 @@
         self._file.close()
         try:
             os.rename(new_file.name, self._path)
-        except OSError, e:
+        except OSError as e:
             if e.errno == errno.EEXIST or \
               (os.name == 'os2' and e.errno == errno.EACCES):
                 os.remove(self._path)
@@ -837,7 +837,7 @@
         path = os.path.join(self._path, str(key))
         try:
             f = open(path, 'rb+')
-        except IOError, e:
+        except IOError as e:
             if e.errno == errno.ENOENT:
                 raise KeyError('No message with key: %s' % key)
             else:
@@ -859,7 +859,7 @@
         path = os.path.join(self._path, str(key))
         try:
             f = open(path, 'rb+')
-        except IOError, e:
+        except IOError as e:
             if e.errno == errno.ENOENT:
                 raise KeyError('No message with key: %s' % key)
             else:
@@ -885,7 +885,7 @@
                 f = open(os.path.join(self._path, str(key)), 'r+')
             else:
                 f = open(os.path.join(self._path, str(key)), 'r')
-        except IOError, e:
+        except IOError as e:
             if e.errno == errno.ENOENT:
                 raise KeyError('No message with key: %s' % key)
             else:
@@ -912,7 +912,7 @@
                 f = open(os.path.join(self._path, str(key)), 'r+')
             else:
                 f = open(os.path.join(self._path, str(key)), 'r')
-        except IOError, e:
+        except IOError as e:
             if e.errno == errno.ENOENT:
                 raise KeyError('No message with key: %s' % key)
             else:
@@ -932,7 +932,7 @@
         """Return a file-like representation or raise a KeyError."""
         try:
             f = open(os.path.join(self._path, str(key)), 'rb')
-        except IOError, e:
+        except IOError as e:
             if e.errno == errno.ENOENT:
                 raise KeyError('No message with key: %s' % key)
             else:
@@ -1843,7 +1843,7 @@
         if fcntl:
             try:
                 fcntl.lockf(f, fcntl.LOCK_EX | fcntl.LOCK_NB)
-            except IOError, e:
+            except IOError as e:
                 if e.errno in (errno.EAGAIN, errno.EACCES):
                     raise ExternalClashError('lockf: lock unavailable: %s' %
                                              f.name)
@@ -1853,7 +1853,7 @@
             try:
                 pre_lock = _create_temporary(f.name + '.lock')
                 pre_lock.close()
-            except IOError, e:
+            except IOError as e:
                 if e.errno == errno.EACCES:
                     return  # Without write access, just skip dotlocking.
                 else:
@@ -1866,7 +1866,7 @@
                 else:
                     os.rename(pre_lock.name, f.name + '.lock')
                     dotlock_done = True
-            except OSError, e:
+            except OSError as e:
                 if e.errno == errno.EEXIST or \
                   (os.name == 'os2' and e.errno == errno.EACCES):
                     os.remove(pre_lock.name)