The usual.
diff --git a/Lib/dos-8x3/mimewrit.py b/Lib/dos-8x3/mimewrit.py
index 0f8b990..754576b 100644
--- a/Lib/dos-8x3/mimewrit.py
+++ b/Lib/dos-8x3/mimewrit.py
@@ -125,4 +125,4 @@
 
 
 if __name__ == '__main__':
-    print "To test the MimeWriter module, run TestMimeWriter.py."
+    import test.test_MimeWriter