diff --git a/product/CMFActivity/ActivityTool.py b/product/CMFActivity/ActivityTool.py
index e0c036d9901387b57404824aab707dbb561b1614..06a914f660838ed6e5c134826151963607028783 100755
--- a/product/CMFActivity/ActivityTool.py
+++ b/product/CMFActivity/ActivityTool.py
@@ -162,7 +162,7 @@ class Message:
     #LOG('notifyUser begin', 0, str(self.user_name))
     user_email = activity_tool.portal_membership.getMemberById(self.user_name).getProperty('email')
     if user_email in ('', None):
-      user_email = activity_tool.email_from_address
+      user_email = getattr(activity_tool, 'email_to_address', activity_tool.email_from_address)
     #LOG('notifyUser user_email', 0, str(user_email))
     mail_text = """From: %s
 To: %s