diff --git a/group/__init__.py b/group/__init__.py
index e69de29bb2..2a357840f6 100644
--- a/group/__init__.py
+++ b/group/__init__.py
@@ -0,0 +1,5 @@
+from signals import *
+from handlers import *
+from models import GroupMessage
+
+grpmsg_added.connect(grpmsg_added_cb, sender=GroupMessage)
diff --git a/group/handlers.py b/group/handlers.py
new file mode 100644
index 0000000000..3cb1d7320e
--- /dev/null
+++ b/group/handlers.py
@@ -0,0 +1,21 @@
+from seaserv import ccnet_threaded_rpc
+
+from signals import grpmsg_added
+from seahub.notifications.models import UserNotification
+
+def grpmsg_added_cb(sender, **kwargs):
+    group_id = kwargs['group_id']
+    from_email = kwargs['from_email']
+    l = UserNotification.objects.filter(msg_type='group_msg',
+                                        detail=group_id)
+    if len(l) == 0:
+        group_members = ccnet_threaded_rpc.get_group_members(int(group_id))
+        for m in group_members:
+            if from_email == m.user_name:
+                continue
+            n = UserNotification(to_user=m.user_name, msg_type='group_msg',
+                                 detail=group_id)
+            n.save()
+    else:
+        pass
+    
diff --git a/group/models.py b/group/models.py
index 79320b8331..31b40a0cb3 100644
--- a/group/models.py
+++ b/group/models.py
@@ -1,6 +1,8 @@
 import datetime
 from django.db import models
 
+from seahub.notifications.models import UserNotification
+
 class GroupMessage(models.Model):
     group_id = models.IntegerField()
     from_email = models.EmailField()
diff --git a/group/signals.py b/group/signals.py
new file mode 100644
index 0000000000..c0c1089bd7
--- /dev/null
+++ b/group/signals.py
@@ -0,0 +1,3 @@
+import django.dispatch
+
+grpmsg_added = django.dispatch.Signal(providing_args=["group_id", "from_email"])
diff --git a/group/views.py b/group/views.py
index 261f65b7e4..cf1c43d0c3 100644
--- a/group/views.py
+++ b/group/views.py
@@ -12,6 +12,7 @@ from pysearpc import SearpcError
 
 from models import GroupMessage, MessageReply
 from forms import MessageForm
+from signals import grpmsg_added
 from seahub.contacts.models import Contact
 from seahub.notifications.models import UserNotification
 from seahub.utils import go_error, go_permission_error, validate_group_name
@@ -140,7 +141,7 @@ def render_group_info(request, group_id, form):
         repos.append(repo)
 
     # remove user notifications
-    UserNotification.objects.filter(email=request.user.username,
+    UserNotification.objects.filter(to_user=request.user.username,
                                     detail=str(group_id)).delete()
     
     """group messages"""
@@ -233,19 +234,10 @@ def group_info(request, group_id):
 
             # clear form data
             form = MessageForm()
-            
-            # add user notification if not exists
-            l = UserNotification.objects.filter(note_type='group_msg',
-                                                detail=group_id)
-            if len(l) == 0:
-                group_members = ccnet_threaded_rpc.get_group_members(int(group_id))
-                for m in group_members:
-                    if request.user.username == m.user_name:
-                        continue
-                    n = UserNotification(email=m.user_name,
-                                         note_type='group_msg', detail=group_id)
-                    n.save()
-                
+
+            # send signal
+            grpmsg_added.send(sender=GroupMessage, group_id=group_id,
+                              from_email=request.user.username)
     else:
         form = MessageForm()
         
diff --git a/notifications/models.py b/notifications/models.py
index df62e473cf..c5d46387ef 100644
--- a/notifications/models.py
+++ b/notifications/models.py
@@ -6,9 +6,9 @@ class Notification(models.Model):
     primary = models.BooleanField(default=False)
 
 class UserNotification(models.Model):
-    email = models.EmailField(max_length=255)
-    note_type = models.CharField(max_length=30)
-    detail = models.CharField(max_length=100)
+    to_user = models.EmailField(max_length=255)
+    msg_type = models.CharField(max_length=30)
+    detail = models.TextField()
     
 class NotificationForm(ModelForm):
     """
diff --git a/views.py b/views.py
index 06260bcbcb..930a377175 100644
--- a/views.py
+++ b/views.py
@@ -547,9 +547,9 @@ def myhome(request):
 
     # user notifications
     l = []
-    notes = UserNotification.objects.filter(email=request.user.username)
+    notes = UserNotification.objects.filter(to_user=request.user.username)
     for n in notes:
-        if n.note_type == 'group_msg':
+        if n.msg_type == 'group_msg':
             l.append(n.detail)
 
     # my groups