fix: Display locked UI for restricted email thread messages (#16512)

Closes #15289 

<img width="410" height="609" alt="Screenshot 2025-12-12 at 1 08 46 AM"
src="https://github.com/user-attachments/assets/34ea73e6-8664-4b59-96ad-3c15d04e148c"
/>

packages/twenty-front/src/modules/activities/emails/components/EmailThreadMessage.tsx

@@ -5,8 +5,11 @@ import { EmailThreadMessageBody } from '@/activities/emails/components/EmailThre
 import { EmailThreadMessageBodyPreview } from '@/activities/emails/components/EmailThreadMessageBodyPreview';
 import { EmailThreadMessageReceivers } from '@/activities/emails/components/EmailThreadMessageReceivers';
 import { EmailThreadMessageSender } from '@/activities/emails/components/EmailThreadMessageSender';
+import { EmailThreadNotShared } from '@/activities/emails/components/EmailThreadNotShared';
 import { type EmailThreadMessageParticipant } from '@/activities/emails/types/EmailThreadMessageParticipant';
+import { FIELD_RESTRICTED_ADDITIONAL_PERMISSIONS_REQUIRED } from 'twenty-shared/constants';
 import { MessageParticipantRole } from 'twenty-shared/types';
+import { MessageChannelVisibility } from '~/generated/graphql';
 
 const StyledThreadMessage = styled.div`
   border-bottom: 1px solid ${({ theme }) => theme.border.color.light};
@@ -53,17 +56,24 @@ export const EmailThreadMessage = ({
     return null;
   }
 
+  const isRestricted =
+    body === FIELD_RESTRICTED_ADDITIONAL_PERMISSIONS_REQUIRED;
+
   return (
     <StyledThreadMessage
       onClick={() => !isOpen && setIsOpen(true)}
-      style={{ cursor: isOpen ? 'auto' : 'pointer' }}
+      style={{ cursor: isOpen || isRestricted ? 'auto' : 'pointer' }}
     >
       <StyledThreadMessageHeader onClick={() => isOpen && setIsOpen(false)}>
         <EmailThreadMessageSender sender={sender} sentAt={sentAt} />
         {isOpen && <EmailThreadMessageReceivers receivers={receivers} />}
       </StyledThreadMessageHeader>
       <StyledThreadMessageBody>
-        {isOpen ? (
+        {isRestricted ? (
+          <EmailThreadNotShared
+            visibility={MessageChannelVisibility.METADATA}
+          />
+        ) : isOpen ? (
           <EmailThreadMessageBody body={body} isDisplayed />
         ) : (
           <EmailThreadMessageBodyPreview body={body} />