doc: fix case/grammar with mailoutbox (#459)

blueyed · timb07 · commit df4a8e8d575a · 2018-05-26T14:30:21.000+02:00
[ci skip]
diff --git a/docs/helpers.rst b/docs/helpers.rst
@@ -267,7 +267,7 @@ Example
 ``mailoutbox``
 ~~~~~~~~~~~~~~~~~~~~~~~~~
 
-A clean mail outbox where django emails are being sent.
+A clean mail outbox where Django emails are being sent to.
 
 Example
 """""""
