The email package version 1.0, prototyped as mimelib

<http://sf.net/projects/mimelib>.  There /are/ API differences between
mimelib and email, but most of the implementations are shared (except
where cool Py2.2 stuff like generators are used).

Lib/email/Errors.py

@@ -0,0 +1,26 @@
+# Copyright (C) 2001 Python Software Foundation
+# Author: barry@zope.com (Barry Warsaw)
+
+"""email package exception classes.
+"""
+
+
+
+class MessageError(Exception):
+    """Base class for errors in this module."""
+
+
+class MessageParseError(MessageError):
+    """Base class for message parsing errors."""
+
+
+class HeaderParseError(MessageParseError):
+    """Error while parsing headers."""
+
+
+class BoundaryError(MessageParseError):
+    """Couldn't find terminating boundary."""
+
+
+class MultipartConversionError(MessageError, TypeError):
+    """Conversion to a multipart is prohibited."""