diff --git a/mailing.py b/mailing.py
index 620afc9..7bc1fe1 100644
--- a/mailing.py
+++ b/mailing.py
@@ -1,4 +1,7 @@
 import requests
+import os
+
+inter_communication_secret = os.getenv("INTER_COMMUNICATION_SECRET")
 
 
 # API call to send mail notification
@@ -12,8 +15,8 @@ def triggerMail(
 ) -> None:
     try:
         query = """
-            mutation Mutation($mailInput: MailInput!) {
-                sendMail(mailInput: $mailInput)
+            mutation Mutation($mailInput: MailInput!, $interCommunicationSecret: String) {
+                sendMail(mailInput: $mailInput, interCommunicationSecret: $interCommunicationSecret)
             }
         """
         variables = {
@@ -23,7 +26,8 @@ def triggerMail(
                 "uid": uid,
                 "toRecipients": toRecipients,
                 "ccRecipients": ccRecipients,
-            }
+            },
+            "interCommunicationCecret": inter_communication_secret,
         }
         if cookies:
             requests.post(
diff --git a/mutations.py b/mutations.py
index f8e5e6f..61dd93e 100644
--- a/mutations.py
+++ b/mutations.py
@@ -2,6 +2,7 @@
 from datetime import timedelta
 from pydantic import HttpUrl, parse_obj_as
 from fastapi.encoders import jsonable_encoder
+import os
 
 from db import eventsdb
 
@@ -37,6 +38,8 @@
     getUser,
 )
 
+inter_communication_secret_global = os.getenv("INTER_COMMUNICATION_SECRET")
+
 
 @strawberry.mutation
 def createEvent(details: InputEventDetails, info: Info) -> EventType:
@@ -604,10 +607,39 @@ def deleteEvent(eventid: str, info: Info) -> EventType:
     return EventType.from_pydantic(Event.parse_obj(upd_ref))
 
 
+@strawberry.mutation
+def updateEventsCid(
+    info: Info,
+    old_cid: str,
+    new_cid: str,
+    inter_communication_secret: str | None = None,
+) -> int:
+    """
+    update all events of old_cid to new_cid
+    """
+    user = info.context.user
+
+    if user is None or user["role"] not in ["cc"]:
+        raise Exception("Not Authenticated!")
+    
+    if inter_communication_secret != inter_communication_secret_global:
+        raise Exception("Authentication Error! Invalid secret!")
+
+    updation = {
+        "$set": {
+            "clubid": new_cid,
+        }
+    }
+
+    upd_ref = eventsdb.update_many({"clubid": old_cid}, updation)
+    return upd_ref.modified_count
+
+
 # register all mutations
 mutations = [
     createEvent,
     editEvent,
     progressEvent,
     deleteEvent,
+    updateEventsCid,
 ]