fixes #4506

src/messaging/notifications.js

@@ -96,7 +96,7 @@ module.exports = function(Messaging) {
 						message: messageObj,
 						site_title: meta.config.title || 'NodeBB',
 						url: nconf.get('url'),
-						fromUserslug: utils.slugify(messageObj.fromUser.username)
+						roomId: messageObj.roomId
 					}, next);
 				}, callback);
 			});

src/views/emails/notif_chat.tpl

@@ -3,7 +3,7 @@
 <p>{summary}:</p>
 <blockquote>{message.content}</blockquote>
 
-<a href="{url}/chats/{fromUserslug}">[[email:notif.chat.cta]]</a>
+<a href="{url}/chats/{roomId}">[[email:notif.chat.cta]]</a>
 
 <!-- IMPORT emails/partials/footer.tpl -->