specialsre, escapesre: In SF bug #663369, Matthew Woodcraft points out
that backslashes must be escaped in character sets.
diff --git a/Lib/email/Utils.py b/Lib/email/Utils.py
index 49232f7..2b8b94f 100644
--- a/Lib/email/Utils.py
+++ b/Lib/email/Utils.py
@@ -54,8 +54,8 @@
 UEMPTYSTRING = u''
 CRLF = '\r\n'
 
-specialsre = re.compile(r'[][\()<>@,:;".]')
-escapesre = re.compile(r'[][\()"]')
+specialsre = re.compile(r'[][\\()<>@,:;".]')
+escapesre = re.compile(r'[][\\()"]')