diff --git a/perceval/backends/core/pipermail.py b/perceval/backends/core/pipermail.py
index <HASH>..<HASH> 100644
--- a/perceval/backends/core/pipermail.py
+++ b/perceval/backends/core/pipermail.py
@@ -63,7 +63,7 @@ class Pipermail(MBox):
     :param tag: label used to mark the data
     :param archive: archive to store/retrieve items
     """
-    version = '0.7.1'
+    version = '0.7.2'
 
     CATEGORIES = [CATEGORY_MESSAGE]
 
@@ -86,9 +86,14 @@ class Pipermail(MBox):
 
         return items
 
-    def fetch_items(self, **kwargs):
-        """Fetch the messages"""
+    def fetch_items(self, category, **kwargs):
+        """Fetch the messages
 
+        :param category: the category of items to fetch
+        :param kwargs: backend arguments
+
+        :returns: a generator of items
+        """
         from_date = kwargs['from_date']
 
         logger.info("Looking for messages from '%s' since %s",
[pipermail] Set category when calling fetch and fetch_from_archive

This patch adds to the params of the fetch_items method the category.
Thus, it allows to handle fetching operations
(fetch and fetch_from_archive) with multiple categories