diff --git a/.travis.yml b/.travis.yml
index 19a5a9f9e..47ca478d4 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,6 +14,7 @@ addons:
       - python-lxml # because pip installation is slow
       - unixodbc-dev
       - python-mysqldb
+      - postfix # some tests want a local mail server
 
 env:
   global: