diff --git a/emailtunnel/__init__.py b/emailtunnel/__init__.py
index fb15c45..a4bceff 100644
--- a/emailtunnel/__init__.py
+++ b/emailtunnel/__init__.py
@@ -26,6 +26,7 @@
 import re
 import six
 import sys
+import copy
 import logging
 import datetime
 import itertools