Have MimeWriter raise a DeprecationWarning as per PEP 4 and its documentation.
diff --git a/Lib/test/test_MimeWriter.py b/Lib/test/test_MimeWriter.py
index feca163..5a20bf2 100644
--- a/Lib/test/test_MimeWriter.py
+++ b/Lib/test/test_MimeWriter.py
@@ -10,6 +10,10 @@
 import unittest, sys, StringIO
 from test.test_support import run_unittest
 
+import warnings
+warnings.filterwarnings("ignore", "the MimeWriter module is deprecated.*",
+                        DeprecationWarning)
+
 from MimeWriter import MimeWriter
 
 SELLER = '''\